Hey, I know that this is an older post... I just stumbled across it after having a similar error. I, too, had a lot that I switched from residential rental to residential after I realized that the lag I was experiencing was from building on a residential rental lot. After saving and exiting my game, attempting to load the following day also rendered me with a BE error message, as well as a perpetual load screen. After fiddling with my mods unsuccessfully for a few hours (I also had a tunable_perf error; as the other commenter mentioned, this is a script mod issue, and will require removing the affected .package file), I removed For Rent from my installed DLC, and was able to load the file as normal.
Of course, the affected lot was blank upon loading. However, I was able to recover the remaining lots and households on my save, and ended up making a new save with all of those after adding For Rent back in. I'm fairly sure you would be able to continue playing on the same save after a re-load, but letting the game register For Rent data as missing seems to be the only fix for this. For me at least, it was not a mod issue.
I can certainly empathize with your frustration. I wish you the best with your save file.
