Over the last few days, I have encountered a serious problem with two silverstripe sites I am managing. It seems like the installation's /sapphire/dev/ folder is spontaneously disappearing or being deleted or something. This leads to a completely non-functional website, either just giving me a blank page, or a fatal error message stating that class Debug could not be found. Simply re-uploading the dev folder and running a ?flush=1 does the trick and everything is back to normal.
As you can imagine, I find this problem quite disturbing. The folder seems to disappear at a time at which no one is using the CMS. Probably (since one of the sites receives very little visitors, and the other one is not live yet) no one is even visiting the frontend site at that time.
Does anyone have any idea as to how this could have occurred? Maybe my hosting provider is screwing around (though that is very, very, unlikely -- many years of faithful service)?
The issue occurred with silverstripe versions 2.3.2 and 2.3.3 running on a Linux/Apache system with PHP 5.2.6 installed.