About 40% of my uploaded image files randomly vanished

Title pretty much says it all. Uploaded stuff over the past few days (I have a plus account and am well within the storage limit), and when I checked some of the pages I'd created, the map images were gone. Looking into the folders, some of the files disappeared completely, while for others the file name is actually still there, but the associated image is gone. It's really weird. There doesn't seem to be a pattern, it's happened in various different subfolders, and some of them are actually still present in the Recently Uploaded folder, but vanished from the pages I'd placed them on nonetheless. What on earth is going on??   I emailed the help desk but I'm still waiting on a previous help request from several days ago, and one of my players has a request they never responded to, so it seemed worth it to post here in case anyone had ideas or a speedier answer. 

There is a button to change the behaviour of the Recently Uploaded folder. It can either: - show only files that you have not in manually moved into your library - show all files you ever uploaded Make sure to show all files and - if an image cannot be found there it does not exist. - if an image can be found but you know its gave issues. Add it to the VTT area, select it and press Z.  Pressing Z should show the image in the original size. Roll20 uploads each image in different sizes from small to large and then as last the original. If this does not yield a good image, then the upload has failed and you need to upload the picture again. Preferably without closing the 'uploading image' window.

Thanks - I didn't know you could switch the Recently Uploaded folder like that, that's very helpful! So some of the files are actually still present in the Recently Uploaded folder, but have vanished from the pages I placed them on. That I can deal with fairly easily. Most of the files however seem to have been deleted from Recently Uploaded as well. I wish I knew why they were vanishing, it's incredibly frustrating since I spent hours re-uploading these files and then the next day a good number of them were just gone. I don't want to re-upload again until I know what's going on and it's fixed.  The only thing that's unusual with these deletions is that many of their names still exist in the folder I moved them to, but with one of those 'broken image' pictures and no affiliated file. In the past when I've been the one deleting things, they just disappear from the folder; I wonder if this is a symptom of whatever system glitch is deleting my files. 

It doesn't sound like this is the issue, but just in case: Moving an image to a folder is actually only moving a marker to the image. There are no real "folders" in the common meaning. I.e. if you move something to a folder and remove it from Recent Uploads, it's gone from everywhere. Recent Uploads is where all the files actually reside.

Right, which is why it was very odd a few days ago when I deleted files from a sub-subfolder and then they all vanished from Recently Uploaded as well! (And yeah, I'm 100% certain that I was deleting from a subfolder and not Recently Uploaded.) Something very wonky appears to be going on with my account. (And of course, no response from the Roll20 to my help request.) Sigh. 

I spoke too soon, I did get a reply from Roll20, saying they'll try to see if the files are still available. It didn't address why this would've happened. I emailed back because while I want the files back, it's more important to me to know why this happened so it doesn't keep happening.