Did I just delete all my photos?

Got a new android phone, and got all my photos transferred over from old to new but wanted to start with a clean slate on the new phone. Booted up syncthing on PC to make sure it was up to date then obviously messed something up trying to get new phone setup with syncthing.

At first it was downloading everything from the PC to the phone and quickly ate up all the space. I changed the folder types to only send from phone to PC.

Eventually errors started popping up. For example, this one is in my log:

[Q47XE] 2024/02/10 18:49:35 WARNING: Error on folder "Camera" (sm-g950u_br9n-photos): folder marker missing (this indicates potential data loss, search docs/forum to get information about how to proceed)

Essentially my _Sync folder on my PC where everything backs up to is pretty much empty. Even some folders not associated with this phones backup were deleted. There’s nothing in the Windows Recycling bin.

Is there a way to fix what I seem to have broken? Either in Syncthing or Windows?

Unfortunately, it’s difficult to say what happened exactly. Following your explanation, even if the disk got full and you changed the folder type, just doing that still shouldn’t have led to any file deletions.

At this point though, if the folders on both sides are empty, and you haven’t enabled file versioning in neither of them, then the files are likely gone indeed. Syncthing doesn’t send them to the Recycle Bin unless configured to do so via the external file versioning.