Virtual machine no longer works after upgrade to VirtualBox 5.1.34

[BarryVG]

I too have the same issue.  Was running Win7, WinXP, Zoin, Debian 9.2, Emmabuntu, Manjaro 1705, Linspire 7.0 and Mint 18.3.  All have failed and slowly working out why.  The update at time was 37 units and took over 30 minutes.  Normally do updates about every 3-5 days, so this was a wonder.  System is Dell M4500 with 8gb ram and i7 processor.