Stuck at "We're getting ready to run your Python code now"

I’ve created a model using Python scripts ( and for behaviors).
When I reset the simulation, I get a “We’re getting ready to run your Python code now…” message with a loading circle icon above it and it’s stuck this way (30min and waiting). Reloading the page didn’t help.
I really don’t know how to debug this or what could be causing it. Any suggestions would be great!

Hi, tritium!

That’s an interesting issue I never encountered before. Could you check if clearing the browser cache is solving this issue? What browser are you using and is the issue persisting on a different browser?

I am experiencing the same issue. I’ve cleared my cache and have tried both Chrome and Safari.

Certain overly aggressive antivirus software and ad blockers may occasionally prevent the execution of WebAssembly code such as that which we use to execute Python in-browser. Please try another browser, and/or disabling these one by one.

If you still then find yourself experiencing issues, feel free to reach out again.