The latest AE Beta crashes when performing evalScript() from an extension panel simultaneously with certain actions in AE itself.
Replication using sample CEP panel from the Adobe-CEP repository:
- Open the AfterEffectsPanel extension in the latest AE Beta
- Open the panel debugger in chrome: http://localhost:7777/
- Navigate to the console tab
- Create a function that calls evalScript:
function fun() {window.__adobe_cep__.evalScript('JSON.stringify(app.project.activeItem.name)', (res) => console.log(res))}
- Call that function on a regular interval:
setInterval(fun, 500)
- Console should be outputting comp name every 0.5 seconds
- Now create a shape layer using the rectangle tool (Q). This is one example of an action that will cause a crash, but there are others.
- AE Crashes and exits:

This is a huge issue for extension developers, so I hope to get some traction on this before the next AE general release.