Honored Contributor
Honored ContributorNormally PLL output names used in assignments do not end in "|c0" or "|c2". If the PLL node names in the first post are the names you have in the Assignment Editor without question marks by them, then I'm guessing those are names created by "keep" synthesis attributes in the IP's HDL, which might make them work in assignments.
However, the tsu and th assignments cannot be made between two clocks. The "th Requirement timing assignment" on-line help page and the similar tsu help page list all the valid combinations of "from" and "to" fields for the th and tsu assignments. None of those combinations is from a clock to a clock.