My MIT app inventor project is not opening it keep loading and then stops,so i cannot access or export my project

Use this to get to the Project List

http://ai2.appinventor.mit.edu/?autoload=false

then

This URL allows you to open AI2 to the Project List, without opening any project.
http://ai2.appinventor.mit.edu/?autoload=false
From that list, you can request Exports of Projects without trying to open them.

If you require repair assistance, upload the aia file here.