Ok, so good news and bad news. The fix for this crash was pretty simple, but after fixing it I found out that something has changed in the GameMaker runtime at some point that has broken something else which stops rendering from working.
The current quick fix (to both issues) is to roll back your runtime - everything seems to be working adequately with runtime 2.3.0.401, other newer runtimes may work too. It's not a perfect solution but it's all I can offer for now. It should at least let you start experimenting with what you can do
Thank you for highlighting this issue for me. Since I'm not sure what specifically is broken, I think it's time for me to raise the priority on doing the complete re-write. It's probably going to take a bit of time since I need to work on it between contract work, but hopefully I can have it in working condition within the next month or two. It should simplify animation/blending and stuff and boost performance, but it will also have a different API (making use of structs and such)