That's a very welcome improvement. It's certainly giving error lines if I miss out a quote mark in a rawcontrolnames array, which significantly reduces the amount of time I'll have to mess around with that particular error.

However, trying to be thorough, it doesn't seem to give a line for all possible errors - the one I'm most fussed about is that it doesn't seem to be able to identify the line if a flex controller has the wrong number of wrinklescale variables compared to its raw controls. (Being honest, that's one of the things I regularly mess up).

I note that it also can't identify the line if I misspell many of the actual commands.
( eg. "accidentally" removing a letter from a rawcontrolnames command gives "Key Error: rawcontrolnames" and a reference to line 316 within the datamodel.py script, but not the line where it happened in the flex controllers.)

Still, I'm a lot less concerned about that latter error, as that's a lot less likely than missing out a quote mark when trying to rename controllers and reorganise flexes.

It'd be very much appreciated if you could.

I love having access to properly merged flex controllers in Source Filmmaker, but it's really frustrating to have to try and debug them completely blind.

I'm listing this as a bug, as I never get any line reference on the Blender console when this error comes up, but it *really* should be giving that information.

A misplaced quote mark or comma would be a three second fix with a line reference, not a manual slog where I have to keep deleting flex controllers and re-exporting until I find the one that was causing the problem.

Whether this is a problem on my end or an oversight in BleST, I don't know. Either way, I'd like to see it fixed.