TYPO3 Core

Not reproducable. Can you reproduce this on a fresh 4.0 installation with dummy-site?

I know tis problem, too...
Version 4.1.1 (fresh with dummy)
at IE and Firefox

some error in "class.t3lib_ajax.php"???

Version 3.8.1 works fine.

It's the first time I'm working with typo3, and I also got this error with a 4.1.1 source+dummy installation.
I found the cause in my case after checking the ajax network traffic with wireshark:

ini_set('display_errors',0) should avoid any error output of alt_clickmenu.php, but in my case this function was disabled and caused some output. Afterwards the contenttype couldn't be set to html/xml and the ajax-stuff failed to parse the error/xml mixture...

Maybe Typo3 should check this issue...

same problem today.. after copy of website (+bdd) from dev to prod ;-(

I need some more information here:

• Does this happen with every TYPO3 installation you have?
• Does this problem still occur with TYPO3 4.1 or even with TYPO3 4.2 alpha?
• Do you use Windows webserver or a Linux machine as server?
• Does it happen with every browser?

Hello

• Does this happen with every TYPO3 installation you have?
  No, just after sysadmin copy file+bdd on another server...

• Does this problem still occur with TYPO3 4.1 or even with TYPO3 4.2 alpha?
  Testing with TYPO3 4.1.2

• Do you use Windows webserver or a Linux machine as server?
  Linux, SLED

• Does it happen with every browser?
  Testing with Firefox.. only ;-(