ERROR c.x.x.d.XWikiDocument Failed to get the default edit mode

I am restoring xwiki on a test instance, from 8.2.1 (old instance backup, Ubuntu 14.04) to 11.9 (Ubuntu 18.04)
I managed to get the wiki up with backup restore.
The thing is now I see all the pages in xwiki but no content. When access a page, I get -

$renderedContent

But when I try to edit the page, I can see the content.

And in the logs I see -

ERROR c.x.x.d.XWikiDocument - Failed to get the default edit mode for [lcsbbiocore:lcsb-sysadmins.Predict-protein]
java.lang.RuntimeException: Error creating extended parser class: null

Any idea on how to solve this?

Best Regards

Hi @maharshi.vyas! Can you provide last strings with errors from tomcat log?