Hey there Tofu,
I apologize for the late response, thank you for being patient! Were you able to fix that crashing issue? If not, I'd be happy to help out, as I can imagine this is pretty annoying to deal with. The first thing I would do is factory reset the Chromecast device. Afterwards, see if you are able to access the settings and then update the Chromecast's firmware.
I look forward to your response, and if you have any other questions or concerns for me, please let me know!