Maya won't save as .mb

I had an issue today where I couldn't save my Maya file as a .mb, and faced the following error:

The Problem:

 "File contains unknown nodes or data. To preserve this information, the current file type cannot be changed. //"

This can be caused by having unknown nodes in the scene, usually from an external plugin that you no longer have.

The Fix:

unknown_nodes = cmds.ls(type="unknown")
# Before you delete, check you want to delete these unknown nodes!
cmds.delete(unknown_nodes)

After running this code, you should be able to save as .mb again!

Maya error- # Warning: 你的文件贼健康~我就说一声没有别的意思 #

My Maya got a virus after opening some dodgy file the other day and rather un-helpfully uninstalled some of my preferences - Yay!

The Problem:

Maya error- # Warning: 你的文件贼健康~我就说一声没有别的意思 #

The Fix:

1. Install Maya Security tools from here: https://apps.autodesk.com/MAYA/en/Detail/Index?id=8637238041954239715
2. Enable MayaScanner.py & MayaScannerCB.py (Windows>Settings/Preferences>Plug-in manager)
   
   
   
3. Delete vaccine.py, vaccine.pyc from /Documents/maya/scripts
4. Open userScript.py and remove the following lines:

import vaccine
cmds.evalDeferred('leukocyte = vaccine.phage()')
cmds.evalDeferred('leukocyte.occupation()')

And that's it - you should be cured!