Sorry to hear you ran foul of this issue. We don't often see loading issues like this and indeed the last one was reported 2 years ago which we never received the save files for.
If possible can you include the details we request in How to: Submit a Bug Ticket and especially the save and .meta files for your save file which does not load. Although we cannot investigate immediately (due to work on other projects) hopefully I can get some eyes on it in our triage pass.
Customer support service by UserEcho