Unable to Preview Transcript
Issue:

Clicking the <Preview Transcript> button results in the following error message:
"The value ‘null’ is not for operator ‘>’. Error is in Expression “{!templateList.size >99}' in component <apex:outputText> in page sdocs:sdcreate1”
Solution:
Please review the formula handling in the Generate Transcript Flow. Ensure that the URL used is correct, and remove the segment "lightningnav=true&" from the respective URL.
Before remove:

After remove:

Finally, save the flow and activate it as a new version to apply the changes.