Nope, not enough clues.
You need to get a call stack and the original Exception to give us something to work with.
It could be that you have made a page that fetch data from another page that fetch data from the original page again.
Shounds like a recusive bug
This error seems to be related to this issue:
Did you find a solution to this? I get the exact same problem after deploying a new CMS 6 R2 site to production. The version is 6.1.379.0.There are no errors in the log nor events in the event viewer. The site is running in .NET 4 in 64-bit environment.
I resolved my problem by replacing the std web.config (with .NET4 changes) with the one from my staging server. Haven't yet figured out which config setting that does the trick. Will try to compare files and post the findings.
Lucia/Thomas - did you figure out the fix for this?
We also have the same problem.
It indicates that something goes wrong when you load the PageData object through DataFactory's method GetPage or GetChildren.
There is not one simple cause for this problem so you must have more clues like an callstack from the exception.
The error is hard to see since it is hidden inside an ajax callback from the Page Tree.
Use a tool like Fiddler or the Net tab to see the call and use Visual Studio and the debugger to catch the exception so you get the REAL exception message and call stack.
Use the strategy described here to attach the debugger, halt on exception and find the cause:
The organization I work for got an internal server error on our site. The problem was that a "reverse proxy server" had some sort of bottle neck that limit the amount of data to be sent in one chunk.
I'am just throwing this out there. Iam very new to developing. Hope you solve your problems!
I was getting a similar error when the tree needed to be updated. This helped me solve it http://world.episerver.com/Articles/Items/EPiServer-CMS-60-now-supporting-ASPNET-40/.
Hope it helps!
I can't expand nodes from structure tree in edit mode.
i am using EPISERVER 6 R2.
Aimen, my guess is that you have a license problem, make sure you download a valid one for CMS 6 from here https://license.episerver.com/
Thank you for your answer. I confirm i have the license error message.
Adding the below attributes to the <pages> tag in web.config fixed the problem for me.
We recently ran into this issue when attempting to access our site through the Content and Structure page on the main site. This error presented itself when attempting to expand the tree for a particular site.
After clicking the plus sign and waiting for a while, the error message ("There was an error in the callback") would appear just below the site name. After receiving the error, another message appear: "Internal Server Error - Sorry, there was an internal error. Please try again later".