Hi!
In the past few days I had two times the problem, that Glyphs refused to save my file. No matter If I try to save it as a new file or under the same name.
Closing the file (loosing all my progress), restart all an trying again didn‘t help. I just can’t save the file. Attached is the message I receive from Glyphs…
Glyphs 3.0.3, MacOS 11.6
Any Ideas?

You seem the enter a number in a spot where an string is expects. Layer/master names, custom parameters?
I think I messed up the Stems settings.
Can you please confirm how the new Stems settings work in comparison to Glyphs 2?
-I first have to set the Icon to vertical or horizontal.
-In the first field I may name the stem.
-In the second field I set the value for the stem.
- I would repeat this for every needed stem value.
Right? 
Thank you!