If you are receiving the below error it is coming from NetSuite and typically means that the account you are connecting to is undergoing maintenance. Often this is a sandbox account and you may want to switch over to your production account.

You can also check the status of NetSuite at status.netsuite.com and CloudExtend at status.cloudextend.io.
​

Check that you are logged into the correct account by navigating to Settings and then checking your account details under account.