What do you mean by your persistent disk?
How did you upgrade to 5.0? Did you do a rip and replace or did you do a straight upgrade?
What is you vSphere version?
What is your VCS version?
What is your vCenter version?
What is your View Composer Version? (Are you using linked clones?)
Can you send a screenshot of where you see this error? I'm just trying to follow where you are.
Sorry for the barrage of questions, hopefully I can help.
Gunnar
Gunnar Berger
http://www.gunnarberger.com
http://www.endusercomputing.com