[T3blank-tpl] Missing button style after upgrade t3b3 framework

[joomlart]

Test on T3blank and T3 plugin v1.4.3

1. Create menu with Display Template Option type, named: Template options
2. Log in the frontend of your site as a Super User.
   3 Click Template Options in the Menu => it's fine
   4, Upgrade T3plugin v1.4.3 to v2.0.0beta
3. Refresh Template option page
   Got error as the attached image