Hello,
This error has been frequently seen in ST on computers lately: folder marker missing. Even after I re-added the .stfolder folder, It still reported this error after a while. The main operation of recent synchronization is to create a symlink to another synchronized folder within one synchronized folder. It is suspected that the synchronization error caused by this operation is reported, but this symlink is required on the computer to facilitate the work, and “junctionsAsDirs” is not checked in the ST advanced settings. This should be a bug, hopefully it can be fixed
More details are needed (e.g. the operating systems, etc.). Are you sure that something doesn’t simply delete the empty .stfolder directory? This is a common problem, e.g. on Android where various phone manufacturer or 3rd party “cleaning” apps like to do just that.
There should be no other softwares that will delete the .stfolder, I just use Obsidian to access sync folders, and the synced folders on my phone has been normal without the .stfolder missing error.
On my computer, the two folders as follows
./folderA
./folderA/symlink of folderB
./folderB
On my Android,
./folderA
./folderB
Do you use relative paths like that? If yes, then please make sure that Syncthing / SyncTrayzor is always started from the same path the folders are supposed to be located in, as those paths are relative to the current working directory.
Can you post a screenshot of the Syncthing GUI with the error message and folder path visible?