I can't access my Dropbox account online due to captcha.

Hi John Bingley, thanks for bringing this to our attention.

Could you try switching browsers to see if this helps?

Otherwise, you can try using incognito/private browsing mode without any extensions running, clearing your cache and even resetting your browser entirely.

Keep me updated with any progress.

What is strange is that sometimes when I try to log in I get the puzzles other times I get a request for a code sent to my phone. That system, the phone code, works perfectly well. 
Today I used both Cortana and Firefox and for both I got the code request that works, no puzzle. 
why do I not get the code request everytime. After all I signed up for that. 

Are you accessing the site via a VPN, or is there an extension which deletes your cookies, or changes your location? Are you running a strict firewall or security software which could be affecting the Captcha?

Regarding the code sent to your phone, that would be for the two-step verification, and would be separate from this behavior.

No, I am not using a VPN and I never change my location. In fact the problem is with my PC at home. With regard to cookies given the choice I always accept only essential cookies on any site. My security settings are no different now than they were before the puzzles began to appear and I just Use Norton Security.

My Firefox settings clear cookies and data when i close Firefox.

The strange thing is that after your message yesterday i logged into Dropbox on Edge and Firefox with no problem just receiving the request for the code sent to my phone. This was the .case just now when I logged in to send this reply.

There appears no logic to the puzzles appearing or not. I can go days without a puzzle appearing and then days when they do.  However, whenever they appear I either cannot complete the puzzle or I am not verified and sent back to the start.

Hey John! Hope you don’t mind me chiming in. I’m glad to hear you’re not having trouble with this anymore. 

In case the same thing starts happening again though, I’d like a screenshot of any errors you get after completing the puzzle/audio quiz. We can further investigate after that.

The puzzles do not appear every time fortunately. I have no problem with the code sent to my phone so I can access Dropbox if the puzzles do not appear.

Fortunately up to now my phone and tables appear to be puzzle free, so i can use them as well.

The next time i am rejected I will take a screenshot and forward it to you. 

Thanks for that, John Bingley, we'll wait for your update.

Once again I was prevented from  completing a puzzle. I  attempted around 60 moves, the attached is just a few of those moves.

https://www.dropbox.com/scl/fi/2reqkugq9t1dzcpx42mur/Dropbox-puzzle.mp4?rlkey=yi59g3g9q6bclhyp4qo19wrfa&st=xviyy7hy&dl=0

Hi all (and dropbox​): I have the same issue. I have spent 20 minutes solving quizzes, never succeeding, and gave up after that. So, maybe changing browser, clearing cache, and private browsing solve the issue temporarily, but the question is: why Dropbox (whose services have been so far impeccable) is using this adversarial method with the poorest user experience score I have ever experienced to sieve humans from robots?

@Dropbox: please stop it, and adopt another one (e.g., the one used by Overleaf seems way better)

Hey John Bingley & Gabriele-Luxembourg!

I just sent you an email, in order for us to have a closer look into this.

I'll see you there, thanks!