Issue
Example:

Resolution
Option 1
Navigate to
1. Salesforce Setup >
2. Quick Find > Session Settings >
3. Trusted Domains for Inline Frames > Add Domain of Nintex DocGen Page >
Please try the following Combinations:
a. https://{MyDomain}.lightning.force.com
b. https://{MyDomain}--loop.visualforce.com
c. https://{MyDomain}--loop.sandbox.vf.force.com
d. https://{MyDomain}--loop.force.com
e. https://{MyDomain}.sandbox.lightning.force.com
f. https://{MyDomain}--c.sandbox.vf.force.com
Option 2
Navigate to
1. Salesforce Setup >
2. Quick Find > Session Settings >
3. ClickJack Protection > Uncheck >
Enable clickjack protection for customer Visualforce pages with headers disabled

4. Scroll down to the bottom and click 'Save'.
5. Navigate back to the record > Refresh the record and run the Flow again.
Expected behavior: Generation bar and download link.

