Update to 3.0.19.8 / vmclasslanguage not found

[Tentaurus]

I tried to update from 3.0.18.x to 3.0.19.8..

First time: I got the error "vmclasslanguage not found"
Second time: empty screen
Third time: OK

Beside this I will do further tests...

[Milbo]

This is strange. I know that some others had also this error. I investigated it and noticed that the old vm installer used the "installed" files and not the new files for the update process. But I fixed this. I did some test update and I know also that others had  no problems anylonger. So I wonder why you got it. Which installation method did you use?

[Tentaurus]

I tried it again.

I restored a 3.0.18.7 backup
Then I installed 3.0.19.8 via Joomla installer.
This time I got a blank screen with the title: "Fehler: 0 Call to undefined method Vm:Table::checkTableExists()"
But refeshing the screen shows 3.0.19.8 as installed...

Then I tried another backup from a different site - same, same!

Then I tried a 3.0.18 backup. Same result!

Language problem (in my case German)?

PHP is 7.0.x