Suddenly the files inside the folder App_Plugins/UmbracoForms have vanished and I cannot seem to recover them. The files include UmbracoForms.config, version, installed as well as the most important form data inside the Data folder.
Checking the file/folder history it seems that the files were last modified by the Application Pool user identity, meaning the website deleted it's own files.
Why would this happen and how is it possible to recover these files?
I've never come across Forms/Umbraco deleting anything out of the App_Plugins folder without a user uninstalling the plugin in the back office.
Is it possible that someone has done a publish via VS or similar that's cleared the folder and replaced it?
In terms of getting the files back, if they've been deleted, you should in theory be able to recover them from your hosting company's back-ups (assuming the site is being regularly backed up).