Another chapter from the book – "Where did my SharePoint files go?"
Okay, this one was a little tough to figure out. The issue was that a user had uploaded a folder to their SharePoint site using Explorer view. The folder was titled "Project_Files". They noticed, however, that after the paste was successfully completed, the standard library view did not show the new folder.
They went back and checked and, sure enough, it could be seen using Explorer view…
…but it was hidden when using the Standard view.
So the folder was there but hidden. It turns out that SharePoint treats file and folder names that end with _files or _file as hidden files (similar to hidden files on your C: drive) so they won’t be visible in the default view. This invalid name extension is on the list of invalid characters for SharePoint 2007 and 2010 – this is a good link to have handy when training users how to move files into SharePoint and can avoid a lot of headaches.
So, how did we fix the problem with this particular hidden folder? Unfortunately, you cannot just rename the folder – SharePoint won’t let you. The solution was to delete the folder (while in Explorer view), then change the folder name BEFORE uploading it to SharePoint. The good news is that the folder and all of its content were also "really there", so no data was lost. And, at the end of the day, that’s always a good thing.