The "arduino" or "www" folder on the SD card gets automatically deleted

Hi everyone,

So the problem has occurred many times, I have a folder for my project on the SD card under the path root/arduino/www/myProject. However sometimes the “www” or even the “arduino” folder will automatically get deleted while I was working on something else. For example when I was working with mjpg_streamer and wants to go back to my project folder, I found the entire “arduino” folder was not there anymore! Has anyone experienced this similar issue or know what might have caused this? It’s really a pain in the ass.

Does it get deleted when you upload a new sketch? Or does it happen randomly?