Fix to the "Must update restart" message
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Find the minecraft.jar file (download link at bottom) in the Lib folder.
Right click it and click "Open With" option an open it with WinRar.
Serach for the "Null" file and delete it
There ya go a way to fix it tested it 8 times on diff comps and worked 100% of the time.
Link: Minecraft.jar file
WoM Coins: 1
Cant seem to open it with winrar at all.