Itch wouldn't let me upload the update as it was just over 1GB (their limit) but I've been in touch with them and they've kindly raised the limit to 2GB so I'm in the process now of re-uploading 0.10.8. Once I'm done there shouldn't be any more errors! :)
EDIT: All done! The update is now hosted on Itch's servers again, just as it was previously. Sorry for the inconvenience!