2502-update may have several bugs and I found one and its solution.
It took many hours for me to find this, so like to share with you hoping anyone with other solutions share it here.
After updating, it seems PAD add passwords to "Open EXCEL file" block. My excel has no password, but PAD tried to open it with those neverknown passwords, so it fails.
Open detail of this block, and remove those passwords will fix this problem.
Regards,
HH