Player informed me today that he was raided. I called bullshit, because I have TruePVE installed and set up correctly, and it's been running fine since the first day of the server. He tells me that 40mm grenades can be used to circumvent TruePVE? I tested it myself by building a structure to sheet metal, then blasting it with 40mm HE grenades ....... and destroyed it.

Any idea why?

It's confirmed ..... HE grenades, C4 and rockets so far damage everything with TruePVE anabled correctly. Just rolled back to a previous version and all is right again.

Thank you for pointing that out!
It's the null checks that were added in OnEntityTakeDamage that prevent the plugin from handling the damage properly.

Fortunately nobody figured it out on my server ;)

I think this is the second time this was added with similar effect.  Will remove again.