Thank you for contacting Adobe Captivate Prime Team.
May I know what are you trying to do here? Are you trying to create a Captivate Prime trial account?
Can you please let me know what are you trying to do and when you are getting the error?
Hope to hear from you soon.
I am experiencing the same issue. I am trying to start a new trial. After completing the "registration", click on submit, receive the "400 Bad Request Request Header / Cookie Too Large openresty" error
I just tested creating a new Trial account and its working fine.
Kindly open the link below in a new incognito browser page. It should work.
Please click on the option "Create an account with Adobe ID". It will ask you to fill the trial form.
Once done it should create the trial account for you.
Kindly let me know if any further assistance is required.