Summary
When Microsoft Office 2013 is activated using an Office 365 license key, the TMAS 7.5 toolbar of WFBS 9.0 doesn't work in Outlook 2013.
Details
This is a product limitation of WFBS 9.0. The TMAS Toolbar of WFBS 9.0 does not support Office 2013 with Office 365 license.
Users can go to the About Microsoft Outlook page in Outlook 2013. If it has "MSO" in the first line, it means that you have a Microsoft installer (MSI) version that the WFBS 9.0 TMAS toolbar supports.
If the page shows "365" in the first line, you have an MSI version that the TMAS toolbar does not support.
A workaround for this issue is to activate Office 2013 with an Office 2013 license instead of Office 365.