Here are 2 issues you might encounter while trying to publish apps that you created based on App Studio source code:
Error on certification report: “The binary HtmlAgilityPack.dll is built in debug mode”
The problem is that (currently) App Studio is using HTMLAgilityPack version 1.4.8 which was built in debug mode (by mistake).
You can resolve this error by updating HTMLAgilityPack to version 1.4.9 via NuGet.
Error when you compile the same solution in Visual Studio:
“Payload contains two or more files with the same destination path ‘HtmlAgilityPack.pdb’. Source files:
To resolve the issue, just change the “Copy Local” property of the HTMLAgilityPack reference to False in the Windows project.