Executive summary ;-)
To avoid WSOD on php 5.4: In panels.module change
This fix is committed but a release isn't coming soon since nobody is maintaining the 6.x branch (seewhere someone actually volunteered to maintain it).
I'm in the process of updating some physical servers which use Windows 2008 R2 as their OS (due to software requirements of the WebApp being hosted) and as such they use the Uniform Server as their secured-for-production WAMP stack.
Once I ported one such WebApp to its new server with the latest Uniform Server (version Coral 8.4.0), everything came up as expected with the only exception being all Panels Pages and Panels Nodes were empty. One such Panels Page that uses the rounded rectangle style for each of the blocks or Views it displays shows up with empty rounded rectangles.
Now, the blocks and Views in the Panels pages appear to be getting called because logic I have in the blocks is getting executed even though the Panels Pages appear empty.
The "only" difference between the version of these sites where Panels behaves normal and where the pages are empty are:
- Updated PHP from version 5.3 to version 5.4
- attempting to see if its fixed in a new version, the "bad" version is running Panels 6.x-3.x-dev 2012-Jan-21
I also have another version of the same site, on the same physical server, running a previous version of Uniform Server. That version's Panels Pages and Panels Nodes display fine...
I've attached a screen shot of one such empty Panels Page (the one that uses rounded rectangles for each block).