Null pointer Exception while trying to run Polypheny-DB

[S-Harshit]

All of sudden my Polypheny-Db has stopped working,
I have forked and clone the repository again and after re-importing it to intellij, it is still throwing null pointer exception while trying to run it.

ERROR -

Task :dbms:PolyphenyDb.main()
13:43:12.038 INFO [main]: InformationServer started.
13:43:15.836 INFO [main]: Making the catalog persistent.
13:43:18.564 INFO [Thread-21]: REST Interface started and is listening on port 8089.
13:43:19.043 INFO [Thread-31]: JDBC Interface started and is listening on port 20591.
13:43:19.059 ERROR [main]: Uncaught Throwable.
java.lang.NullPointerException: null
at org.polypheny.db.catalog.CatalogImpl.lambda$restoreColumnPlacements$2(CatalogImpl.java:358) ~[catalog-1.0-SNAPSHOT.jar:?]
at java.util.stream.Collectors.lambda$uniqKeysMapAccumulator$1(Collectors.java:178) ~[?:?]
at java.util.stream.ReduceOps$3ReducingSink.accept(ReduceOps.java:169) ~[?:?]
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1654) ~[?:?]
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[?:?]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[?:?]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913) ~[?:?]
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?]
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578) ~[?:?]
at org.polypheny.db.catalog.CatalogImpl.restoreColumnPlacements(CatalogImpl.java:358) ~[catalog-1.0-SNAPSHOT.jar:?]
at org.polypheny.db.PolyphenyDb.runPolyphenyDb(PolyphenyDb.java:215) ~[classes/:?]
at org.polypheny.db.PolyphenyDb.main(PolyphenyDb.java:90) [classes/:?]

[vogti]

Hi @S-Harshit This should not happen... But it sometimes does when you switch branches or deploy adapters (e.g. a CSV adapter) and then delete the directory. Since Polypheny-DB is persistent and restores data and schema on startup, there can be errors when the previous configuration can't be restored. The good thing is, that this error is easy to fix: Simply start Polypheny-DB ones with the -resetCatalog parameter.

We already have it on the to do list to make the startup procedure more stable and resilient.

[S-Harshit]

It fixed it,
Thank You