Errr...i have the WHMCS WP Integration plugin installed but it's not in the list of plugins above or on my WPMU Dev Dashboard. ?? I did update it this morning and it appears to be still installed (v1.4.4). Since upgrading to WHMCS 7.1.1 I'm getting the message below. I have confirmed that I have the correct theme selected in WHMCS and have tried the other options without success.
Sorry this doesn't look like a WHMCS site at [https://hosting.rocksolidhq.com/] Make sure your WHMCS Integration settings are pointing to the correct URL and that the WHMCS site is set for the Portal template in Setup | General.