I had this happen to me too. It's clearly a bug with so many people dealing with it. I had three vampires stuck there in sunlight and only the testing cheats motives hack kept them alive. I had the same message about vampires breaking in but they were trying to go home. I have been afraid to let any of my vampire seniors leave the Hollow now because of this happening, in case they cannot get home, so it severely restricts their movements if they do not have sunlight immunity.
The way I solved it in the end in my game was to disband the group, somehow, when the option was eventually available, but they still didn't go home. However by doing this it allowed me to go back to the main house menu. I went to their house but they were all absent and it was not possible to load the house without them there so I couldn't call them home. I ended up moving in a random sim to that house so that I could load the house, and thus call them home. Two of them had to go to school so fortunately they automatically trotted off there and from that point were able to go home. In the case of the third sim, she eventually came home by herself but it was worrying. This also precipitated one of those vampires becoming invisible for which I had to repair the game in order to make him visible on the screen again (he had an avatar but no physical presence in the house).
Since repairing the game I haven't dared take any sun-prone vampires out to those kinds of venues so I have no idea if it is a problem. I had a sun-safe vampire visit a human in a different neighbourhood and he was able to go home safely, but that was a home and not a community lot so I don't know whether it matters.
My sims were a long way from the lot in question when they got stuck, they were walking along a very long path and then stopped and couldn't go any further because of that message. I don't know if a NPC vampire was breaking in to the community lot or if this was some other bug preventing them going home, but I would've thought that if it was the former the solution would be to stop vampires breaking into community lots?
Either way the last post on this issue was apparently January, I had the problem in this August just gone so it would be great if there was a fix to prevent it in a future patch...