Description in 1.101 & 1.102 firmwares says "CPU serial 17X0001 or higher" and mine is 1660420 so skipped those.
Global label is 3896 and MAIN program 48564 bytes, so shouldn't be a problem.
It's pretty odd that sometimes it handles a lot of changes, but sometimes fails at simple changes. Like.. adding OR-block with 2 labels (that already exists) without connecting OR to anything. And sometimes it works when adding more complex edit like several AND, SET, RST, MOV, comparisons and many labels.
I have tried several thing to find what is causing it, but still no idea since sometimes (too often) it fails with simple changes... :)
Maybe will still try to divide program to smaller pieces. Thanks for the help!