Typically this error indicates that the URL the user (your applicant) is trying to access is invalid. We have come to see that many times an applicant will provide our clients with a link which does not look like the below:

https://grantrequest.com/SID_12345?SA=AM

The above is what your Online Application account link should look like when received by applicants. However, because of online security, some applicant's mail servers will add on additional text to the web address of the account link when a merge field is used in your email template for the Account URL. To remedy this issue you can approach the matter in 1 of 2 ways:

1. You can inform your applicant that their mail server is appending text. They may want to bring the matter to their IT department that manages the mail server to try to whitelist the contents of the email so it is not appended by security. 

2. You, as the GIFTS user, can manage your email template to not use a merge field for the Online Application Account URL. This allows the URL to pass mail servers unaltered. 

Example here:

Instead of : please click on the following to access your account <<My_Account_URL>>

Use this: please click on the following to access your account: https://grantrequest.com/SID_12345?SA=AM (please note that '12345 is a placeholder. Please insert YOUR Online Application Site ID in its place)