Unable to undo pending changes, and other weirdness

[Olmy]

So I'm trying to undo a pending change so I can continue working in a branch (currently it's in a broken state). The change is a deleted file, and when I check it, and click undo, nothing happens. I've resorted to having someone send me the deleted file so that Plastic detects it as being in the unchanged state, but this looked like a bug to me so I looked into the issue a bit. When I go to the Items in workspace tab, the file's status is Controlled / Not on disk.  I'm absolutely certain the file is on disk, I can see it in explorer.  

 

This is where it gets weird, I also noticed another file is missing that shouldn't be, and is not being detected as deleted in pending changes. I'm certain I didn't check in a deletion for this file, so I pressed Update workspace to try and get that file back. Here's the result :

 

http://i.imgur.com/icM2QeF.png

 

The missing file is main.unity. I assume this client version error is why it's also not detecting changes properly, and undo is not working.

 

I'm currently using 5.4.16.619 - Nottingham client , and this error only started appearing in the last 2 days.

 

[Olmy]

I just tried updating to 5.4.16.623, but the situation is basically the same, I now have a bunch of changes that I can't undo.