OK, I am wasting a lot of time trying to get this working...
Here is what I found:
1) Apple appears to only let you create ONE iOS development certificate, and only TWO App Store and Ad Hoc certificates.
2) Contrary to what seems to be said in the instructions, you CAN NOT create a "Ad Hoc" certificate, then create an "iOS App Development" provisional file. Proof of this is that if you created an "App Store and Ad Hoc" certificate, then select "iOS App Development" when you create a provision file, when it gets to "select" certificates screen, you will notice ONLY your "iOS Development" certificate is listed (your app store/ad hoc certificate is NOT listed).
This step is why my Build B4-bridge was failing with the above error, because I was creating a provisional file using a certificate that was NOT created with B4i (my existing iOS development certificate was created outside of B4i using another product).
So, I then created a new provision file, but selected "Ad Hoc" on the first screen, then when I got to the "select certificates" screen, it properly listed my "App Store/Ad hoc" certificate that I created for B41. Now the Build B4i-Bridge app compiled OK.
So far so good.
I then installed the B4i profile (using b4x.com/ca.pem) and it installed OK.
I then typed the IP address given in the "build b4i-bridge" compile result dialog and it properly displayed a "Install App" circle and I clicked it. A new bridge icon appeared on my 5s's homescreen, but then it displayed an error "Unable to install app - B4i_bridge could not be installed at this time".
So I go to the profiles section of my 5s and it lists:
Configuration Profiles:
B4i - Verified
Provisioning Profiles
B4i Dev - Verified (the name I gave the provisional "ad hoc" provision file)
So, why wont it install?
Is it because the certificate and provision files were create with "ad hoc" selected? If so, then how can existing apple developers (with an existing App Development Certificate created outside of B4i) use B4i to compile apps?