Conor McGregor is opening up on the scrapped UFC 303 press conference that was scheduled for Monday ... and while he didn't explain exactly why it was canceled, he did say it was the result of a number of problems.
Notorious and Michael Chandler were slated to talk some trash in Dublin to promote the June 29 event ... but just hours before it was all supposed to go down, the organization confirmed it was a no-go until further notice -- without providing any more information.