Did you end up with a session timeout message while trying to create a NetSuite Connection using ExtendSync for Google NetSuite? Here are possible reasons why you might end up in a session timeout.
Symptoms
Connection Creation flow gets halted with a session time out during the Three-Step Authentication flow.
While creating a new NetSuite connection using the app, you might end up in a session time-out screen, not being able to proceed with the connection creation.
Cause
One of the possible reasons for the connection creation process to get halted and a timeout is reached due to the fact that you may have accidentally double-clicked on the Allow button while providing permission. This would end up the whole connection creation process to stuck and a time-out is reached.
You may also end up in the same situation if you had kept your Three-Step Authentication popup unattended for a longer time also.
Workaround (Make sure you click on 'Allow' button once)
If your connection creation process gets timed out, try the steps below;
Step 1: Close the already opened Connection Creation pop-up.
Step 2: Start creating a connection again via Connection Creation menu in the app.
Step 3: Make sure to complete the connection creation process in one go.