In a JSX file, emmet expansion (tab) is not working in JSX file, when we are positioned after self-closed tag (like <a/>).
There are some limitations in Xemmet unfortunately. It passes the whole string to the Emmet core and it automatically extracts the abbreviation and in some cases this might fail. I guess it should work in Emmet but I don’t have enough time to dig in the code. As a workaround, you can extract your abbreviations on a new line and then concatenate them.
How to add Emmett in Komodo like before ?
Emmett was working flawlessly in previous versions of Komodo.
The old emmet addon is not maintained and thus not compatible with the current Komodo version. Your best bet is to appeal to @Defman to fix the but in Xemmet or to work on an Emmet addon yourself.