error when running DCDiag.exe

returns error:

dcdiag.exe – Entry Point Not Found : The procedure entry point DsIsMangledDnW could not be located in the dynamic link library NTDSAPI.dll.

does it have to be run from the PDC-E FSMO role holder? or will any Domain Controller do? The reason I ask is, I’ve used this command on my main DC for years without a problem. I recently reorganized the FSMO roles and now it fails on that computer (only holding the roles of “Schema, Domain naming master”). the command works fine on the new PDC-E holder, however I also just installed the support tools on that server to test it.

can anyone verify this? dcdiag.exe works on DC not holding PDC-E role?

an ideas?