Appointment + Plugin does not save Service Providers

When I want to add new 'Service Provider':

1st: Under 'Select Services' dropdown Check All link does not work

2nd: If I select services manually and click 'Save Service Providers' it does not save anything

So, I can't add any Service Providers at all no matter how I do it...

Any suggestions???

I am using the latest plugin... version 1.3