completely ruined the file and filled it with strange symbos
and in worst case it had done some memory leak and crashed the whole

I encountered this bug some time ago but not seen that in two recent betas. Now
I'm using the latest one,
790 (viz https://forum.pspad.com/read.php?6,78417 ).

PSPad freeware editor https://www.pspad.com

Odpovedet emailem