Fabrik 3.8.1 has been released. It is mostly bug fixes and feature enhancements, but does include two new plugins (push notifications, and the sequence element). As usual we strongly recommend testing the new release on a sandbox if your application is mission critical, and always do an Akeeba backup before updating.
A quick Wiki entry to point out that if you are using Bootstrap fabrik templates, then you probably need to be using a bootstrap Joomla templates like Protostar.
This is particularly true if you are using Tabs in your list or Bootstrap_Tabbed form or details templates as the tab functionality is provided by the bootstrap functionality.
If you particularly want to use bootstrap-only Fabrik 3.1 functionality like Tabs in a non-bootstrap template, you can try installing a Joomla extension like this to include bootstrap in your HTML anyway.