If you use our SQL, Twain, LibXL, DynaPDF and other functions relaying on library files, be sure to have those in 64-bit, too. If you don't have TAPI driver in 64-bit, you should keep your solution running as 32-bit.
For the syntax coloring in FileMaker, the MBS Plugin can still overwrite FileMaker's colors and provide much more flexible rules for colors. Like red color if a called script is missing or checking calculation syntax to highlight wrong brackets.
With MBS FileMaker Plugin 5.0, everything should work already as we tested a lot with beta versions. With 5.1 we will probably fix a few minor things we'll encounter in the next days.
If you like to try, use our 5.1pr7 release: Prerelease Download
Enjoy the new version, test it and please email us if you see an issue.