Unable to install flavor - archive is not a ZIP archive

Hi
I am installing xwiki using docker and connecting to postgres installed on the host machine(Ubuntu 16.04). I am facing a strange issue when installing flavor. For some reason, xwiki is not able to download extension archives. It throws the error saying that extension archives are empty.

Flavor%20Installation%20Issue

*2019-06-06 12:30:20,941 [localhost-startStop-1] ERROR arInstalledExtensionRepository - Failed to parse extension [org.xwiki.platform:xwiki-platform-notifications-ui/10.11.8] *
java.util.zip.ZipException: archive is not a ZIP archive

  • at org.apache.commons.compress.archivers.zip.ZipFile.positionAtEndOfCentralDirectoryRecord(ZipFile.java:958)*
  • at org.apache.commons.compress.archivers.zip.ZipFile.positionAtCentralDirectory(ZipFile.java:883)*
  • at org.apache.commons.compress.archivers.zip.ZipFile.populateFromCentralDirectory(ZipFile.java:621)*
  • at org.apache.commons.compress.archivers.zip.ZipFile.(ZipFile.java:295)*
  • at org.apache.commons.compress.archivers.zip.ZipFile.(ZipFile.java:218)*
  • at org.apache.commons.compress.archivers.zip.ZipFile.(ZipFile.java:201)*
  • at org.apache.commons.compress.archivers.zip.ZipFile.(ZipFile.java:162)*
  • at org.xwiki.xar.XarPackage.(XarPackage.java:160)*

Although the UI says that flavor is installed, after login, I don’t see it is being installed. It presents me with empty wiki.

I got into the docker shell and I checked if I can download extensions manually using curl and I am able to do that.

What could have caused this issue?

Thanks
Ganesh

After reinstalling postgres, it worked fine.