It seems to be version compatibility issue on server. Did you created this project in 11.6 or upgraded it?
If its an upgrade and you still have old version, then try deploying on old version first to verify th error.
Mendix fixed this in the MX 11.6.1 update recently. I had the same error with 11.6 version, but it's fixed after upgrading to MX 11.6.1.