"Why Managing Document Versions in SharePoint is So Hard (and What to Do About ...
Error Loading Survey: You have not been given permissions to complete the survey
If you have created a SharePoint survey and users are receiving an “Error loading survey” message or “You have not been given permissions to complete the survey” message when trying to access and complete the survey as shown below:

You can solve this by ensuring that all users (that are required to complete the survey) have Contribute permissions on the site and library that contains the survey.
If the survey has been created by DocSurvey and the survey task has been assigned to a specific group of users using DocRead then it will be relatively easy to check the relevant permission levels of the entire group involved.
Here are some recent posts you may find interesting:
"Why Managing Document Versions in SharePoint is So Hard (and What to Do About ...
DocRead vs PowerDMS: Policy & Training Tools Comparison Many organizations already pay for Microsoft ...
DocRead vs PowerDMS: Policy & Training Tools Comparison Many organizations already pay for Microsoft ...
"Why Managing Document Versions in SharePoint is So Hard (and What to Do About ...
"Why Managing Document Versions in SharePoint is So Hard (and What to Do About ...