for redo this issue, you can open info window from any where.
after that you focus to a parameter and quick enter many time
mandatory is a slow connection or slow server.
this condition let server do query many time and make issue by some variable will has state unsync with process.
because i can't redo this issue at my machine (it's very fast), patch i commit in experimental is for "try"
tested in experimental, solution is resolve issue
Tested OK - test case fails on test.idempiere.org but works fine on experimental.idempiere.org