We upgraded our Qlikview to version April 2020 (12.50.20000.0) and after that some errors happened related to block chart objects. The error does not appear while opening the document via Internet Explorer plugin. The chart is really simple and does not include complex expression or large amount of data. I think this version of Qlikview has a lot of bugs and is not stable.
the error appears in Chrome (the chart is very simple and the error does not related to expression):
The same object while being opened via Internet Explorer plugin (everything is ok when we open it via IE plugin):
I have same problem with Line chart object in this version and I have to opened my source Doc and pressed Reset user Sizing and Reset User Docking buttons for each Line chart object and Published again Then may problem not repeated in chrome Browser but this solution not worked for my block chart objects 😐