Upgrading from 3.8.9 to 5.2.0 - Blank 'Grey' Background Page When Done

[skicdave]

Wow... well its been 3 full days fighting this upgrade on a new CentOS test server before I run it on my production server in a few weeks.
Converting 3.8.7 on a test server to 5.2.0.

CentOS 7, Apache/2.4.6, MariaDB 5.5.44, php 5.4.16

Google searches thankfully shed light on a bunch of issues that can occur and I have finally been able to get the database converted on 5.2.0.

At this point the conversion is done and I can get into admincp and all looks ok, however when I go to the forum home page I just get a 'nearly' blank page. Its the same textured grey background you see here on www.vbulletin.com.

No apache errors.

The page source code attached in image.

Any idea where to start looking?

Thanks

Dave

[skicdave]

Anybody have any ideas? Into my 5th day trying to get 5.2.0 working... getting very frustrated! Have not been able to locate any solutions, or starting points. I'd hate to have to start debugging vBulletin code...

[Craig]

Open a trouble ticket, if you haven't done so yet.

[skicdave]

Yes I did open a ticket.