The NextGEN button is not working in visual editor

Um, but you see the button right ?

I’m unfamiliar with Ultimate TinyMCE and Online Marketer.

You can try re-installing nggallery over the existing version.

Don’t uninstall.

Occasionally some people here run into an oddball problem and they deactivate, and reactivate nggalery, which sometimes fixes the problem.

Otherwise you’ll have to try with the default theme, and deactivating all plugins and activate nggallery with one plugin in at a time to see what breaks nggallery.

Kinda hard to guess, you’ll need to include more details.

Good luck.