This is a very old thread but for the last few posts here is the thread you are looking for with current information.
Re: iCal will not send if location is added to event
Since late November/Early December 2016, many people have not been able to send event invitations when the add a "suggested Apple Maps location" which seems to be blocking the invitation. Read the thread above for other people who have had the same issue.
As i said, this has been happening to me since late November/Early December.
I was manually adding some December/January Calendar events (adding suggested Apple Maps locations) and the inviting a couple family members. After about three invites to events, the invitations stopped going through. One other did go through but it had "TBD" as the location.
Fast foreward: Tonight I removed the suggested Apple Maps locations and left only location names and the invites began to flow! I was able to reproduce it as described above and below in every instance.
1. Both macOS Sierra & iOS 10.2 Calendar apps are affected in my case.
2. It only has happened to me with using suggested Apple Maps locations.
3. I have had no problems with Emojis nor adding notes, only with suggested Apple Maps locations.
I was able to create an event then invite without a location on macOS. After accepting I could modify it on an iOS device and add a suggested Apple Maps location. The the invite would then update to the suggested Apple Maps location for the invitee.
I wonder if my initial action of sending multiple event invites in a short time triggered some anti-spam block in iCloud servers? This began around the same day Apple announced it was going to start actively blocking spam invites. My hope is that I have not been put of some spam list.
I submitted a bug report to the Calendar Engineering Team. It was quick and simple. Hopefully they will find the bug/spam filter issue and fix it soon.