When updating Everest while running Celeste earlier through the in-game updater, it would go all the way through unzipping each file and restart. But the update would not actually install.
I tried again with Olympus a few times to no avail. After doing so, Celeste does not run, even after a restart of my computer. According to Epic, it tries to sync with Cloud, is labeled as "running" for a few seconds, then syncs again. I only saw any process named Celeste running in task manager one time out of a few trials, and even then it was as a background process.
As far as I can tell, the update is failing in the later processes of the updater. I have included an excerpt from log-sharp where I believe the errors are occurring, starting from Line 326.
#Everest Update 4465 Failing. Celeste no longer opens.
shrewd ruin
icy sparrowBOT
As of the Everest Core update, Everest tries to create symlinks in order to share these two folders between the vanilla and modded installs of the game:
Saves, to sync save data between vanilla and moddedContent, to avoid making a duplicate of all the game assets and save about 1 GB of storage space
However, creating a symlink requires admin privileges on Windows. Installing Everest will still work if you choose not to give admin privileges, but you won't get the benefits listed above.
Creating the symlink can also fail on external drives that use non-NTFS filesystems (such as some flash drives). Installing Everest 4482 or later will still work on these filesystems, but data will not be shared between vanilla and modded. If this is an issue, moving your Celeste install to the C drive should fix it.
boreal jay
(specifically the last paragraph)
shrewd ruin
Thank you!
Reinstalling my game onto my C drive worked.
Too bad I lose portability, but it's not like I carry the drive with me often, let alone have the space for Epic on my laptop anyways :P