VSIX broken after signing
In my projects I use a file named LICENSE, without file extension. This file is part of the VSIX container.
After signing the extension it is no longer installable; the VSIX installer complains Microsoft.VisualStudio.ExtensionManager.MissingPackagePartException: The package does not contain the software license agreement that is specified in the extension manifest (License).
Investigating the differences I found that the signing changed the [Content_Types].xml inside the VSIX file; however it did not just add the needed extensions for signature files, but also removed the override for the license file:

Removing this Override entry from the unsigned package leads to the same error message, so this seems to be the root cause.
Can you please file this over at https://github.com/vcsjones/OpenOpcSignTool? That's the library that's doing the VSIX signing.
In the interim, can you work around this by renaming the license file to add a file extension?
Maybe a dup of https://github.com/vcsjones/OpenOpcSignTool/issues/76?
Yes, that seems to be the root cause. For now I have just renamed the file inside VSIX to *.txt, so that's not a blocker.