Invalid file type when trying to import Code Lists

[dpw1460e]

Hi there,

the other day I installed the eu_einvoice module on my test instance running ERPNext 15.47.1 (Frappe Framework 15.51.0) and everything worked fine.

Today I installed the module on my production instance (ERPNext 15.47.3, Frappe Framework 15.51.1), and get the following error message when importing any of the code lists mentioned in the description: File “UN_ECE_Recommendation_N_20_3.xml” was skipped because of invalid file type.

I use the button “Import Genericode” to select the file. Unfortunately, I could not find any error logs or any hint to find out what the problem is. Any idea what could be wrong.

Already removed the app and installed it again. No change. The error persists.

Any idea what the issue could be? Do you need additional information?

Thanks for your help.