Q. Add-Ins Tab not appearing after opening PHStat in Excel.

I went to where the PhStat.xlam file is located.
Right click on the file, select Properties and then at the bottom I saw:
"Security: This file came from another computer and might be blocked to help protect this computer".
There is an Unblock check-box next to this.
Check this and the security message disappeared.
Then double click the file or open from within Excel and it worked as before.