no content in documents after changing from 6.3 to 6.4

When opening my documents and sheets made with calc or writer v 6.3 there is under v 6.4 no content in the opened documents. Some formating things like different field sizes but no content in words or figures.
I am in linux lubuntu 64bit.

I am in linux lubuntu 64bit.

Did you update Lubuntu to version 20.04 as well?

Yes I changed from debian 10 (LXDE) to Lubuntu 20.4


you are on an Ubuntu 20.04 based system (Lubuntu 20.04) using LibreOffice Version: in an initial install scenario - hence check the following questions

which seem to be completely unrelated but share the same solution.