How to increase performance/reduce lag?

I have a super project with multiple scenes. One of the scenes is kinda huge. It works fine if I click on it, but switching from another scene just makes the whole thing crash. Last time I tried this, I lost all my costumes from some weird glitch.

How can I increase performance, either by coding better or doing something else?

can we see th e project

I’m not sure, but I do know that touching color [#880088] ? blocks can slow things down

posted