Module and custom content contain tlk that cannot be merged

So i try to use the update utility for prc but it doesn’t want to work.
cannot merge
I am getting this message when i want to merge prc with gladiatrix module.
When try this on swordflight module it works fine.
Anyone have any clue what is causing this?
Thanks for the info,
Cheers

I understand that PRC respond to queries on their Discord channel.