[QA] cannot access or upload files

[jnweiger]

Seen with files_external_dropbox 1.2.0 on core 10.10.0

• Upload some files into your dropbox account.

• Create an app 'jw-qa' at http://www.dropbox.com/developers with access to the entire account.

• Copy paste the key and secret from there,

• Paste the https://OWNCLOUD_SERVER_NAME/index.php/settings/admin?sectionid=storage url into Redirect URI

• Connect a 'Dropbox V2' external storage with key and secret. After an oauth roundrip, the storage is green. OK.

• Check contents of storage. It is empty. BAD

• Try create a text file via Web UI text editor. An error occurs. BAD
  

• Try upload a jpg file via Web UI. An error occurs. BAD
  

• Try upload a file via desktop client. an error occurs. BAD
  

Expected behaviour:

• Dropbox storage works (before upgrading to core 10.11 and guzzle7 etc..)

owncloud.log has:

{"reqId":"b54e0a73-80e7-44b1-9a5e-5c172bcb48a9","level":0,"time":"2022-07-31T23:54:19+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"OC\\Authentication\\Token\\DefaultTokenProvider::getToken","method":"PUT","url":"\/remote.php\/dav\/files\/admin\/DropboxV2\/testfile.ott","message":"token f341e2d4dc17e9ca021daa3f138c04dbef46dfa8c4c2c1bcc5b4015dcbf6f3f7a3c6f3e1dc066a7e7838d3495a59c2371199b470e79f450af9c799d8d4136573 does not exist"} {"reqId":"b54e0a73-80e7-44b1-9a5e-5c172bcb48a9","level":2,"time":"2022-07-31T23:54:23+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"core","method":"PUT","url":"\/remote.php\/dav\/files\/admin\/DropboxV2\/testfile.ott","message":"ignoring lock release with type 1 for files\/da0340298b7cbd6c8600d6dcb3629354. Lock hasn't been acquired before"} {"reqId":"b54e0a73-80e7-44b1-9a5e-5c172bcb48a9","level":4,"time":"2022-07-31T23:54:23+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"webdav","method":"PUT","url":"\/remote.php\/dav\/files\/admin\/DropboxV2\/testfile.ott","message":"Exception: HTTP\/1.1 500 File not found at path: testfile.ott.ocTransferId1595978521.part: {\"Exception\":\"Sabre\\\\DAV\\\\Exception\",\"Message\":\"File not found at path: testfile.ott.ocTransferId1595978521.part\",\"Code\":0,\"Trace\":\"#0 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Connector\\\/Sabre\\\/File.php(282): OCA\\\\DAV\\\\Connector\\\\Sabre\\\\File->convertToSabreException()\\n#1 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Connector\\\/Sabre\\\/Directory.php(173): OCA\\\\DAV\\\\Connector\\\\Sabre\\\\File->put()\\n#2 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/Server.php(1098): OCA\\\\DAV\\\\Connector\\\\Sabre\\\\Directory->createFile()\\n#3 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/CorePlugin.php(504): Sabre\\\\DAV\\\\Server->createFile()\\n#4 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/event\\\/lib\\\/WildcardEmitterTrait.php(89): Sabre\\\\DAV\\\\CorePlugin->httpPut()\\n#5 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/Server.php(472): Sabre\\\\DAV\\\\Server->emit()\\n#6 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/Server.php(253): Sabre\\\\DAV\\\\Server->invokeMethod()\\n#7 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Server.php(349): Sabre\\\\DAV\\\\Server->start()\\n#8 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/appinfo\\\/v2\\\/remote.php(31): OCA\\\\DAV\\\\Server->exec()\\n#9 \\\/var\\\/www\\\/owncloud\\\/remote.php(165): require_once('\\\/var\\\/www\\\/ownclo...')\\n#10 {main}\",\"File\":\"\\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Connector\\\/Sabre\\\/File.php\",\"Line\":702}"} {"reqId":"b54e0a73-80e7-44b1-9a5e-5c172bcb48a9","level":4,"time":"2022-07-31T23:54:23+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"webdav","method":"PUT","url":"\/remote.php\/dav\/files\/admin\/DropboxV2\/testfile.ott","message":"Caused by: {\"Exception\":\"League\\\\Flysystem\\\\FileNotFoundException\",\"Message\":\"File not found at path: testfile.ott.ocTransferId1595978521.part\",\"Code\":0,\"Trace\":\"#0 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/league\\\/flysystem\\\/src\\\/Filesystem.php(210): League\\\\Flysystem\\\\Filesystem->assertPresent()\\n#1 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Flysystem.php(104): League\\\\Flysystem\\\\Filesystem->rename()\\n#2 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/Wrapper.php(281): OC\\\\Files\\\\Storage\\\\Flysystem->rename()\\n#3 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/PermissionsMask.php(86): OC\\\\Files\\\\Storage\\\\Wrapper\\\\Wrapper->rename()\\n#4 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/Wrapper.php(281): OC\\\\Files\\\\Storage\\\\Wrapper\\\\PermissionsMask->rename()\\n#5 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/Availability.php(295): OC\\\\Files\\\\Storage\\\\Wrapper\\\\Wrapper->rename()\\n#6 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/Encryption.php(270): OC\\\\Files\\\\Storage\\\\Wrapper\\\\Availability->rename()\\n#7 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/Wrapper.php(281): OC\\\\Files\\\\Storage\\\\Wrapper\\\\Encryption->rename()\\n#8 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_trashbin\\\/lib\\\/Storage.php(107): OC\\\\Files\\\\Storage\\\\Wrapper\\\\Wrapper->rename()\\n#9 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/Storage\\\/Wrapper\\\/Wrapper.php(576): OCA\\\\Files_Trashbin\\\\Storage->rename()\\n#10 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Connector\\\/Sabre\\\/File.php(271): OC\\\\Files\\\\Storage\\\\Wrapper\\\\Wrapper->moveFromStorage()\\n#11 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Connector\\\/Sabre\\\/Directory.php(173): OCA\\\\DAV\\\\Connector\\\\Sabre\\\\File->put()\\n#12 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/Server.php(1098): OCA\\\\DAV\\\\Connector\\\\Sabre\\\\Directory->createFile()\\n#13 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/CorePlugin.php(504): Sabre\\\\DAV\\\\Server->createFile()\\n#14 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/event\\\/lib\\\/WildcardEmitterTrait.php(89): Sabre\\\\DAV\\\\CorePlugin->httpPut()\\n#15 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/Server.php(472): Sabre\\\\DAV\\\\Server->emit()\\n#16 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/sabre\\\/dav\\\/lib\\\/DAV\\\/Server.php(253): Sabre\\\\DAV\\\\Server->invokeMethod()\\n#17 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/lib\\\/Server.php(349): Sabre\\\\DAV\\\\Server->start()\\n#18 \\\/var\\\/www\\\/owncloud\\\/apps\\\/dav\\\/appinfo\\\/v2\\\/remote.php(31): OCA\\\\DAV\\\\Server->exec()\\n#19 \\\/var\\\/www\\\/owncloud\\\/remote.php(165): require_once('\\\/var\\\/www\\\/ownclo...')\\n#20 {main}\",\"File\":\"\\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/league\\\/flysystem\\\/src\\\/Filesystem.php\",\"Line\":389}"} {"reqId":"b54e0a73-80e7-44b1-9a5e-5c172bcb48a9","level":1,"time":"2022-07-31T23:54:23+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"core","method":"PUT","url":"\/remote.php\/dav\/files\/admin\/DropboxV2\/testfile.ott","message":"cleaning stray exclusive locks for files\/da0340298b7cbd6c8600d6dcb3629354"}

Maybe related: #135

[jnweiger]

@kiranadh1452 In #137 (comment)
you say, dropbox upload / download works for you in core 10.10 . Do you have any idea what could be wrong in my case?

[kiranadh1452]

@jnweiger

I tried this again, it is still working.
Just to be sure, did you provide read/write access from the Dropbox app ?

We need to provide the access listed under Individual Scope in the dropbox app at https://www.dropbox.com/developers/apps/info/your-app-key#permissions

[jnweiger]

Thanks Kiran for double checking.
Yes, I already tried clicking all permission checkboxes. But that does not help.

It seems a bit random. Sometimes it works right from the beginning, sometimes it does not.
The working setup from yesterday night, now also fails.

{"reqId":"YueJ@pRO37tmmURCS1m3ggAAAAk","level":3,"time":"2022-08-01T08:08:27+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"files_external_dropbox","method":"PUT","url":"\/index.php\/apps\/files_external\/globalstorages\/3","message":"Exception: {\"Exception\":\"Kunnu\\\\Dropbox\\\\Exceptions\\\\DropboxClientException\",\"Message\":\"{\\\"error_summary\\\": \\\"expired_access_token\\\/..\\\", \\\"error\\\": {\\\".tag\\\": \\\"expired_access_token\\\"}}\",\"Code\":401,\"Trace\":\"#0 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/DropboxClient.php(161): Kunnu\\\\Dropbox\\\\Http\\\\Clients\\\\DropboxGuzzleHttpClient->send()\\n#1 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Dropbox.php(273): Kunnu\\\\Dropbox\\\\DropboxClient->sendRequest()\\n#2 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Dropbox.php(243): Kunnu\\\\Dropbox\\\\Dropbox->sendRequest()\\n#3 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Dropbox.php(1227): Kunnu\\\\Dropbox\\\\Dropbox->postToAPI()\\n#4 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/lib\\\/Storage\\\/Dropbox.php(209): Kunnu\\\\Dropbox\\\\Dropbox->getCurrentAccount()\\n#5 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/External\\\/LegacyUtil.php(207): OCA\\\\Files_external_dropbox\\\\Storage\\\\Dropbox->test()\\n#6 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external\\\/lib\\\/Controller\\\/StoragesController.php(254): OC\\\\Files\\\\External\\\\LegacyUtil::getBackendStatus()\\n#7 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external\\\/lib\\\/Controller\\\/GlobalStoragesController.php(189): OCA\\\\Files_External\\\\Controller\\\\StoragesController->updateStorageStatus()\\n#8 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(170): OCA\\\\Files_External\\\\Controller\\\\GlobalStoragesController->update()\\n#9 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(89): OC\\\\AppFramework\\\\Http\\\\Dispatcher->executeController()\\n#10 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/App.php(100): OC\\\\AppFramework\\\\Http\\\\Dispatcher->dispatch()\\n#11 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/Routing\\\/RouteActionHandler.php(47): OC\\\\AppFramework\\\\App::main()\\n#12 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Route\\\/Router.php(344): OC\\\\AppFramework\\\\Routing\\\\RouteActionHandler->__invoke()\\n#13 \\\/var\\\/www\\\/owncloud\\\/lib\\\/base.php(914): OC\\\\Route\\\\Router->match()\\n#14 \\\/var\\\/www\\\/owncloud\\\/index.php(54): OC::handleRequest()\\n#15 {main}\",\"File\":\"\\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Http\\\/Clients\\\/DropboxGuzzleHttpClient.php\",\"Line\":59}"}
{"reqId":"YueJ@pRO37tmmURCS1m3ggAAAAk","level":3,"time":"2022-08-01T08:08:27+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"files_external_dropbox","method":"PUT","url":"\/index.php\/apps\/files_external\/globalstorages\/3","message":"Caused by: {\"Exception\":\"GuzzleHttp\\\\Exception\\\\ClientException\",\"Message\":\"Client error: `POST https:\\\/\\\/api.dropboxapi.com\\\/2\\\/users\\\/get_current_account` resulted in a `401 Unauthorized` response:\\n{\\\"error_summary\\\": \\\"expired_access_token\\\/..\\\", \\\"error\\\": {\\\".tag\\\": \\\"expired_access_token\\\"}}\\n\",\"Code\":401,\"Trace\":\"#0 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/guzzlehttp\\\/guzzle\\\/src\\\/Middleware.php(69): GuzzleHttp\\\\Exception\\\\RequestException::create()\\n#1 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(204): GuzzleHttp\\\\Middleware::GuzzleHttp\\\\{closure}(*** sensitive parameters replaced ***)\\n#2 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(153): GuzzleHttp\\\\Promise\\\\Promise::callHandler()\\n#3 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/TaskQueue.php(48): GuzzleHttp\\\\Promise\\\\Promise::GuzzleHttp\\\\Promise\\\\{closure}(*** sensitive parameters replaced ***)\\n#4 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(248): GuzzleHttp\\\\Promise\\\\TaskQueue->run()\\n#5 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(224): GuzzleHttp\\\\Promise\\\\Promise->invokeWaitFn()\\n#6 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(269): GuzzleHttp\\\\Promise\\\\Promise->waitIfPending()\\n#7 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(226): GuzzleHttp\\\\Promise\\\\Promise->invokeWaitList()\\n#8 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/promises\\\/src\\\/Promise.php(62): GuzzleHttp\\\\Promise\\\\Promise->waitIfPending()\\n#9 \\\/var\\\/www\\\/owncloud\\\/lib\\\/composer\\\/guzzlehttp\\\/guzzle\\\/src\\\/Client.php(123): GuzzleHttp\\\\Promise\\\\Promise->wait()\\n#10 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Http\\\/Clients\\\/DropboxGuzzleHttpClient.php(57): GuzzleHttp\\\\Client->send()\\n#11 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/DropboxClient.php(161): Kunnu\\\\Dropbox\\\\Http\\\\Clients\\\\DropboxGuzzleHttpClient->send()\\n#12 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Dropbox.php(273): Kunnu\\\\Dropbox\\\\DropboxClient->sendRequest()\\n#13 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Dropbox.php(243): Kunnu\\\\Dropbox\\\\Dropbox->sendRequest()\\n#14 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/kunalvarma05\\\/dropbox-php-sdk\\\/src\\\/Dropbox\\\/Dropbox.php(1227): Kunnu\\\\Dropbox\\\\Dropbox->postToAPI()\\n#15 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/lib\\\/Storage\\\/Dropbox.php(209): Kunnu\\\\Dropbox\\\\Dropbox->getCurrentAccount()\\n#16 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Files\\\/External\\\/LegacyUtil.php(207): OCA\\\\Files_external_dropbox\\\\Storage\\\\Dropbox->test()\\n#17 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external\\\/lib\\\/Controller\\\/StoragesController.php(254): OC\\\\Files\\\\External\\\\LegacyUtil::getBackendStatus()\\n#18 \\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external\\\/lib\\\/Controller\\\/GlobalStoragesController.php(189): OCA\\\\Files_External\\\\Controller\\\\StoragesController->updateStorageStatus()\\n#19 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(170): OCA\\\\Files_External\\\\Controller\\\\GlobalStoragesController->update()\\n#20 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/Http\\\/Dispatcher.php(89): OC\\\\AppFramework\\\\Http\\\\Dispatcher->executeController()\\n#21 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/App.php(100): OC\\\\AppFramework\\\\Http\\\\Dispatcher->dispatch()\\n#22 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/AppFramework\\\/Routing\\\/RouteActionHandler.php(47): OC\\\\AppFramework\\\\App::main()\\n#23 \\\/var\\\/www\\\/owncloud\\\/lib\\\/private\\\/Route\\\/Router.php(344): OC\\\\AppFramework\\\\Routing\\\\RouteActionHandler->__invoke()\\n#24 \\\/var\\\/www\\\/owncloud\\\/lib\\\/base.php(914): OC\\\\Route\\\\Router->match()\\n#25 \\\/var\\\/www\\\/owncloud\\\/index.php(54): OC::handleRequest()\\n#26 {main}\",\"File\":\"\\\/var\\\/www\\\/owncloud\\\/apps\\\/files_external_dropbox\\\/vendor\\\/guzzlehttp\\\/guzzle\\\/src\\\/Exception\\\/RequestException.php\",\"Line\":113}"}
{"reqId":"YueJ@5RO37tmmURCS1m3gwAAAAk","level":0,"time":"2022-08-01T08:08:27+00:00","remoteAddr":"89.204.135.225","user":"admin","app":"OC\\User\\Session::validateToken","method":"GET","url":"\/ocs\/v2.php\/apps\/notifications\/api\/v1\/notifications?format=json","message":"token 6bffcb506fce651cd21743a74814d0af7ad4e2078d64228306832138319dc213ecf1545116cf56a4d8e458f29291b97c50b9b13dd58b839c178688f0995bed00 with token id 4 found, validating"}

Maybe it is really a token refresh problem, as asumed in #135 .

[jnweiger]

Multiple issues are adding up here. Disentangling:

• Some permission settings on dropbox side require an extra click on a small confirmation button, that was hidden at the bottom of the screen.
• Folders appeared empty due to [QA] files_external_dropbox never checks for changes #141
• [QA] overwriting existing files is unreliable #144

Followups in individual issues. Closing here.