Customers using the CSP Trusted Sites feature may receive a 500 or 502 server internal error if the HTTP header size exceeds the limit of 8 KB. We recommend that you review your trusted sites, deselect directives that aren't relevant for the site and use the wildcard character (*) when appropriate to reduce repetition.
Step-by-step guide
Navigate to the Salesforce Setup:
If you’re using Lightning Experience, click the settings icon, then select Setup Home.
If you’re using Salesforce Classic and you see Setup in the user interface header, click it.
If you’re using Salesforce Classic and you don’t see Setup in the header, click your name, then select Setup.
Enter "CSP Trusted Sites" in the Quick Find box, then select the appropriate page from the menu.
Search for the following entries and delete them by pressing "Del" under the "Action" column on the specific row of the listed entry:
Now, let’s edit the CSP Directives for the remaining entries. Search for the following entries and edit them by pressing "Edit" under the "Action" column on the specific row that the entry is listed:
Under General Information, enter Giphy as the Trusted Site Name and https://*.giphy.com as the Trusted Site URL.
Under CSP Directives, check the checkboxes next to "Allow site for connect-src" and "Allow site for img-src", and uncheck the rest of the checkboxes. Press “Save & New”.