Catchable fatal error: Argument 1 passed to t3lib_div::array_merge_recursive_overrule() must be an array, null given, called in D:\xampp\htdocs\t3\r2\

Getting stuck with TYPO3 4.2Beta1 caused by an fatal error after installing dam. To solve the problem remove dam from your extensionlist in localconf.php and wait until Jean has posted his Patch for 4.2 in TER.