Over the past few days some Windows users reported the same thing to us: after normal use, CNC Code stopped launching. Not an occasional error. It simply wouldn't open, and it wouldn't open on the next attempt either. Anyone caught in this situation found themselves locked out of their own program without having done anything wrong, and that's the kind of problem that bothers us the most.

We found the cause, and it's worth telling because it's less exotic than it seems.

A two-line file

CNC Code keeps aside a small file with the interface preferences: the chosen language, the last view, just a few things. That file gets rewritten from scratch every time something changes. If, at the exact moment it's being rewritten, the computer shuts down, goes to sleep, or the program is force-closed, the file stays the right length but with nothing but emptiness inside.

Upon reopening, the application goes to read it, finds nothing readable, and stops. And since that file stays exactly as it is, it stops the next day too, and the day after that. A tiny detail that blocks everything.

What we changed

Now, before even reading it, the application takes a look at that file. If it's unreadable, it sets it aside and launches anyway. Only the interface preferences are lost, such as the language: licenses, projects, programs, and tool libraries all stay right where they were.

We also went a step further, so that a problem like this can't happen a second time: starting with this update, the application writes its files either whole or not at all. There's no longer a middle state where a file seems to exist but doesn't.

In the same update we've also closed two other sudden crashes that had been reported to us: one happened while dragging the scroll bar as the list below was being rebuilt, the other when opening a menu while a screen was still coming in. Cases lasting just an instant, hard to reproduce on demand, and precisely for that reason, annoying to find.

If this happened to you and you haven't updated yet

You can unblock the application right away. Close CNC Code, press the Windows key and the R key together, paste this into the "Run" box, and hit Enter:

%APPDATA%\it.benstudios\cnc_code

A folder will open. Delete the file with that name and reopen the program. You'll only lose the interface preferences.

Thanks to those who spoke up

A problem that occurs intermittently, on a single machine, can only be discovered if someone takes the trouble to write to us about it. Those who did saved us weeks of work. If you come across something that doesn't add up, opening a ticket from the app is the fastest way to let us know: every report genuinely lands on our desk.