Well, I know that this mod is already long time ago. And just to point out the error here is it doesn't create ragdoll for some reason.

Was it the regular Tank or the Sacrifice Tank that had the ragdoll issue? Or both?

I took a look at the mod from testing its ragdoll on the Tumtara map to playing on Official Valve servers to see if the ragdoll was missing. I also checked to make sure that I didn't have any files that would add/change the Tank's ragdoll on my end. I had no other files; the ragdoll appeared for me.

Have you made sure that you don't have any other mods that may be conflicting with this? I know there can be some Campaigns that can sometimes mess up other models if they aren't disabled when playing in other maps - IE: 2019 II: Director's Cut has an issue where having it enabled while playing any other map causes Nick's suit to become full black and have missing textures to his holster. Perhaps you have a Campaign that replaces the Tank's model and Ragdoll which is creating the issue?

If you're still getting the issue, I would disable every mod including this and see if the Default Tank ragdolls.

Sorry for half a year late response, I might need to check out the ragdoll again