Hello, the same problem: Internal Server Error at admin panel when trying to use demo files and installing of Go pricing plugin. Also blank website after demo contact import.
The problem still is active. When i access to Pages appears this:
<b>Fatal error</b>: Allowed memory size of 268435456 bytes exhausted (tried to allocate 83 bytes) in <b>/home/milani82/public_html/wp-includes/wp-db.php</b> on line <b>2224</b>