I've been facing an issue with one of the custom developed webparts in our Sharepoint Environment, after an upgrade from sharepoint 2010 to 2016. This webpart worked flawlessly in 2010 before the upgrade.
I've attached the screenshot of the error displayed below, when I try to open the page containing the webpart.
I've even deleted the existing page, rebuilt my webpart code with the sharepoint 2016 dlls, redeployed it to me site and added it on the new page, but it hasn't worked. Also, when I check the code of the webpart (developed with CSOM), there isn't any "HtmlTableCellCollection" or "asp:LabalCell" in the files.
It would be a great help if someone could shed light on how to fix this issue.
Thanks in Advance!