We upgraded IDM from 12.5 SP17 to 12.6.5 and in any create user task we found this error:
Failed to execute SynchronizeAttributesWithAccountsEvent. ERROR MESSAGE: For input string: ""
I din't find it in known issues or fixed but when I googled the error, I found a link to a CA doc but fails to open.
We solved the issue by upgrading IDM to 12.6 SP7