I need help on downloading Captivate.  I just started subscribing yesterday.  But wen I click download, the message that I got was "413 Header Length too Large."  What does that even mean?

Make sure you have cookies enabled and clear your cache.  If it continues to fail try using a different browser.

Which browser are you using?

Google is your friend

How do I clear caches and cookies? | Apple Support Communities

I was running into this yesterday and today as well, on a brand new Mac (so no way it was a caching issue!), I could not purchase the subscription using Chrome. But opening up Safari worked fine for me.

Hi There,

I apologize for the inconvinience. You may try different browser and see if you are still getting the same error. In case you still get the issues you can Chat with us by clinking on the following link :  Chat
with an Expert . In case you still get any issues then email us directly at tcssup@adobe.com and we will respond you back with the download links.

Regards,

Mayank