IndexSizeError: Index or size is negative or greater than the allowed amount

[lopis]

I can't even start the game. In the title screen, after a couple seconds, I get the following error:

IndexSizeError: Index or size is negative or greater than the allowed amount

Environment: Firefox 68, Ubuntu 18.10

That saddens me because the game seemed really promising.

[yeonjuan]

@lopis
Thanks. May be, Loading state of images needs to be checked.