Customers experiencing issues from Mail Merges may have found several reasons for the error. Here are some common troubleshooting steps to explore to check for issues with their Mail Merge.
Merge Fields have changed
Merge fields from imported lists or synchronized lists from List Management have changed
Customers utilizing imported or synchronized lists may have many more mail merge fields available to them to be utilized in their email campaigns. However, if the lists have changed fields that are either renamed or missing, this can lead to errors since the field can no longer be found. The campaign must then be reformatted to utilize the new fields or remove the missing fields. Please see Personalizing Your Communications With Merge Fields for more information about using merge fields.
Links are improperly formatted
Sharepoint links are too long because they have been copied or shared outside of Microsoft's prescribed methods
Customers may have accidentally copied a file URL instead of utilizing Microsoft's recommended Sharepoint's Share Link function to share files. This causes an error because the URL length is too long, and customers also have the possibility of accessing the file with incorrect credentials, leading to access denied issues.
Copied links have additional information, such as SafeLinks and link verification information
When copying links from sources, customers should review the link source to ensure they are not copying and using a link with "added" information.
For example, if a customer is copying a link from an email they have received, they should consider going to the website and getting the original link. In an organization utilizing Microsoft Safelinks, the link will start with https://[customerurl].safelinks.protection.outlook.com/. The link will then be extremely long and contain additional information, which will cause future problems for your company's security checks. The original URL would normally be something much shorter, for example, starting with https://cnn.com.