Custom Multifield is not working In AEM 6.3

seen error because we have customised the dialog, i have updated the customised dialog with 6.3 updates its started working.

Thanks.

This typically happens because 2 xtypes have the same namespace and therefore AEM tries to load both.  I've seen this with ACS Commons installed (with their multifield panel) and also a custom multifield being installed.

I am seeing an error too in 6.3. This works in 6.2. I am investigating. It may be a bug.

Uncaught RangeError: Maximum call stack size exceeded

    at instanceGenerator._addListeners (composite-multifield.7ad2e3d05f614dfeab0290e74ff2d9

I will post back my findings.

What error in the browser are you seeing?

Custom Multifield is not working in AEM 6.3?

This is very vague.

This is also the reason you don't implement custom multifields, because the API's are constantly changing.