Wow, that sounds like a rather unhelpful error message.

If you open up the console, do you see any Javascript error messages?

No, I don't. I did search this site, though, and found it is not an uncommon error, but inconsistent means to fix it (and none of the methods I found work!)

What I did, for now (which worked around the error and the site is now displaying,) is to comment out the 5.6 directory designation in config/site.php and reassign it to the 5.5 directory. This worked successfully, but is not a viable long term solution.

I can take a look in a few hours if you would like.
On 4 Feb 2013 14:24, "concrete5 Community" <discussions@concretecms.com>
wrote:

Fascinating error. :)

I googled it and found two major potential reasons. One is that an exception gets thrown in a error handler, but this does t seem likely for c5. The other is trying to serialized weird stuff (objects)into a session. Slightly more likely.

First, you should check the php info. You can do this while the site is working. Make sure you've got a recent version of php, and that all the other stuff looks ok. You can compare to a working installation. Look at SQL stuff, session stuff, etc.

Next, browse through all site specific code. Packages, libraries, etc. male sure nothing is particularly hacky.

After that, start adding dies line by line.... :)

Best,
James SHANNON

Sent from my phone