Let's make it clear.

As Chrome has different root folders for Bookmarks, keep in mind the following:

- Chrome Toolbar = Firefox Toolbar

- Chrome Other bookmarks = Firefox Bookmarks Menu

- Firefox Other bookmarks = THERE IS NO SUCH FOLDER in Chrome. That's why you can't transfer Firefox "Other bookmarks" folder to Chrome browser. You can only sync Firefox Other Bookmarks folder to our server or other Firefox browser.

Try to login on everhelper.me

I'm also mac user and don't have such problem. Do you see any Chrome message before the extension turns off? 

Does you Mac goes to Sleep mode or Energy Saving mode?

When does it hapeen? After each restart? Or suddenly during browsing?

What is your OS and Chrome version?

Если Вы имели в виду  галерею готовых изображений для популярных сайтов, то мы исправили эту проблему.

We've fixed this problem. It works now. Thank you for your report!

Do you still have this problem?

Hello! We'll try to fix it ASAP

А что произойдёт, если Вы откроете меню дила (правый клик -> Редактировать) и выберите другой тип превью?

Можем ли мы попробовать Team Viewer ?

Try to reinstall the addon, please. Save your data via backup or sync first.