Oh crap.
MagicLauncher says that the Optifine JAR that I've selected is invalid.
I went back to download an older one, but it doesn't like that one either.
These are the two that I've tried:
OptiFine_1.8.8_HD_U_F5.jar
OptiFine_1.8.8_HD_U_G7.jar
Praytell what sort of boneheaded thing have I done to invalidate this process?
Thx
...