Going to new map on a resumed game still breaks

[DrkSephy]

If I continue from a resumed save file and then beat the map, I've seen the following two errors:

That one occurred on the dev branch on localhost. As soon as the map started, I suspended the game, then resumed and beat the map. When the second map tried to load, that was the error (Firefox).

On the actual game that is being served, I was shown these errors in the console with the same above steps:

[DrkSephy]

After re-trying twice, now it seems to work (tested on the actual game).

I'm really not sure what to say. This needs more feedback.