Error 500 when trying to add New invoice

When I want to open/start New invoice this message is showed:
Oops! Something went wrong
500 Internal Server Error
We will work on fixing that right away.

What can I do?

I use Akaunt cloud and not my own server!

I got this error today on a fresh hosted environment. Enabled debug, looked at logs, errors in code. No fix, no solution. After reading the lack of responses throughout these forums it's unlikely you'll get an answer. I write this as a partial review of the product ... 3/5 ... choose something else.

Max, thanx for your answer.

And my message to Akaunting support: One big "NO COMMENT" to you. You know what I mean.

I have the same situation in the Akaunting cloud and in the self-hosted version. It's useless without that function and shows a very weak system. I do not understand how something so basic in an accounting system is not solved and there is not even any signal from the developers.