Hi all
after upgrading the server to version 2019.2 when a workflow started on the gallery no result is shown.
I get the messages below.
But in the workflow results I see, that all is done but I can't load the results..
What should be the problem
1st message
2nd message
Also I can't load the results 
I get the same error message when I want to upload a workflow to the Gallery (Format Exception, RequestID:xxxx) from the Designer.

The workflow seems to be uploaded correctly.