that really shouldn't be needed, but i don't see full stacktraces of that nullpointer, i don't get that, you should get that if i look at the code, we report the full exception
what are the things you do around:
onSolutionOpen_my_solution:56 (onSolutionOpen_my_solution)
or
my_solution/forms/my_solution_form2/mRefresh:25 (mRefresh)
?
But without the full stacktrace (do you see those on the admin page?) i can't really see what is going on.
But if you have a reproducible test case/solution please make a case.