I have a lot of builds that use a version number generated by the version number plugin. The property is not available in BM 1.0.5 but it works in version 1.0.3:

Example: Use "create a formatted version number", environment variable "civersion"

Add a shell task:
echo $civersion
--> This works well

Add a BM 1.0.5 task:
setpref targetPlatformPath=${civersion}
--> BM complains about the syntax, a value after the equals sign is required.