Hiya's,
XP11 pb4 came out a while ago
Don't update from pb3 until the newer pb4 is fixed
Two errors for others and myself, though some just one error
It throws up a GLSL shader error and/or a Navdata error too
Tony
Edit : Looks like they've pulled pb4
So if you have updated and obviously fubar'ed
Just run the installer and it will send you back to a pb3 state
Tony