Failed to load resource: the server responded with a status of 500 (Internal Server Error)

@Agzem,

I've been trying to reproduce the problem but unfortunately, I couldn't.

I set up an APM-server with a custom index name. Check how it looks when I run the _cat API:

This is the indices page on APM:

Have you created a new index pattern on Kibana settings? If yes can you browse your transactions on Kibana Discover?