Please don't send exception reports to forum!!! Send it to support mail. Your problem is corrupted PSPad.INI file. It can happen in the past but it has incfluence of the 647 and newer.
Send me PSpad.INI to mail, I can check it, fix it and send you it back, if you don't have older backup -- <https://forum.pspad.com/read.php?2,76031,76034> PSPad freeware editor https://www.pspad.com