Error 0x80EE003E

Value: -2131886018 | 0x80EE003E | 2163081278

What does it mean ?

RTC_E_OPERATION_WITH_TOO_MANY_PARTICIPANTS  
The operation failed because of too many participants in the session
Value: 62 | 0x003E | 0b0000000000111110

Where does it come from ?

FACILITY_RTC_INTERFACE  
RTC - Real-time Communications
Value: 238 | 0x0EE | 0b11101110

Other Errors for FACILITY_RTC_INTERFACE