The plugin is compatible with WP 4.7 and WC 2.4.12.
Unfortunately we have not got enough information to tell you what is the problem.
Please answer the following questions:
What did you do when the tabs are disappeared?
Did you upgrade WP or one of your plugin? Did you changed any setting, or install any new plugin?
There should be a reason of this change.
Is Product Tabs menu displayed in WP Admin area?
If you edit a product, can you see the editor fields of tabs? Are they contain any content?
Please check all of your settings.