This topic is also posted on issue #6903
Syncthing uses a marker folder to detect whether the synced folder is mounted correctly. The default marker folder name is .stfolder, and the newly created marker folder is hidden by default, ideally non-tech users won’t see this marker folder. It is changeable in Advanced page:
New users (even some amateur tech guys) usually don’t know about the marker folder behavior, cause they’ve never seen such a name during adding and setting a sync folder, so they may not pay any attention to the .stfolder.
After some accidently operation, such as a cleaning (especially non-tech users love cleaning using some cleaning softwares which delete empty folders by default), a script, the .stfolder might be deleted, and these users will come to ask the same, simple, stupid question: My folder marker is missing, the syncthing stopped syncing, how do I do? Why syncthing need a .stfolder? I hate the .stfolder, can I delete it? …
The reality is, few users really read the FAQ or search the same question before asking for help. Only a few users know they could change marker folder in advanced setting in WEB UI.
To decrease the possibility of meeting the problem described above, I propose 2 solution:
add an option to the Settings panel: the file versioning is enabled, set the folder marker to be same as versions path, which is .stversions. And make the option on by default.
add an option to change the marker folder to the Advanced tab in Add Folder dialog. Instead of only put it in Advanced setting page because it’s too deep to open.
By doing so, users at least could have a glance at some information about marker folder while they config the syncfolder settings.
And by setting the marker folder to the versions path when it’s on could reduce the possibility the marker folder being deleted accidently.
The whole idea is to reduce the chance that users get confused by missing marker folder and then asking the repeated question. That’s all.