Have you searched the net for the error number?
Just go to a search engine and type the error in quotes and hit enter.
Here s what I found:
"Error 7007
A close operation is pending on the session."
there is an old thread for this but it never was resolved"
http://forum.thegamecreators.com/?m=forum_view&t=122911&b=21
It seems that there may be an fault causing an operation not to close. This could occupy the buffer so that no new operations can start. Like placing a new entity.
I am not a programmer but I am good at looking stuff up.
Good luck!!
Patience and tolerance are the keys to the passage of knowledge. Even the ones that know the most started with many questions.