Mongodb.open failure causes access to address 404

Today, when editing the function of the article found a problem, edit and save the completion of the current article to jump to the address, the results of 404, the break point found when the query database Mongodb.open method failure. Baidu after found the reason:

Edit save when the database opened, but not closed, the next query when the database is open state, resulting in a query failure.

Why Mongodb.open after no close operation can not open again, follow-up study and then add.

Mongodb.open failure causes access to address 404