After updating to the latest version 3.4.1 (3435) all plugins crash and fonttools is no longer recognised (although installed). My attempt to re-install fonttools via the plugin manager results in another error:
There is a problem with timeouts when cloning from GitHub that sometimes leaves the installed files in an incomplete state. Maybe an update was going on and then Glyphs was restarted …
As Florian said, we are working on improving this.
Thanks, but is there a workaround? Many scripts and plugins rely on a working fonttools installation in Glyphs. The one I have on the system works as expected.