Hi,
Most likely the ybts module is not loaded.
Try 'status ybts' or 'status mbts' in the rmanager console. If it's showing as a result
%%+status:ybts
%%-status
then you don't have the module loaded.
Check your configuration and that the path from where you're loading modules contains ybts.
You can check from where yate tries to load modules by typing in rmanager the command 'status engine' and look at the 'modulepath' parameter .