When selecting an initial rating or clicking "Take our Survey" within a survey email, the Landing Page loads with the following maintenance/construction error message:

 

https://{domain}.force.com is down for maintenance.
Sorry for the inconvenience. We will be back shortly. Please email us if you need to get in touch.

 

As the last section of this documentation explains, the Default Web Address in the Setup Wizard must match the one in Salesforce Site Setup. This may occur when testing in a Sandbox, where the Simple Survey Setup Wizard displays the URL for the Production environment, or vice versa.

From Salesforce Setup, check the URL for the Simple Survey site.



This address should match the Default Web Address in the Simple Survey Setup Wizard (see below).



Once these match, retest the survey link to verify the Landing Page loads without issue.