BPL files are usual dll files and are well supported by Enigma Protector.
But due to specific of the file, some protection features can't be used with such kind of files.
BPL files are being loaded by the developed program while, for example, debugging using standard Delphi debugger. The protection option Checkup - AntiDebugger determines that a debugger is found and does not allow protected file to be executed.
So Checkup - AntiDebugger should be disabled for protecting of BPL files.