CAPTCHA Security is a built in self defect mechanism in the App to prevent abusive use of the service (like being used by bots).
You may get this CAPTCHA security prompt if you create many files very quickly or logged in the app from different devices within a very shot time. Normally you may get it after creating 15-20 files in a row. Once you verify the CAPTCHA once you are good to go for 15-20 files again. But if you are often getting the CAPTCHA security prompt, kindly try the following troubleshooting steps:
1. Make sure you logged out your account from all devices.
2. Make sure you cleared cache and deleted cookies of your browser before logging in again.
3. Make sure you are not editing a same file again and again.
4. Make sure you are giving it some time before creating a new file as such behavior can be interpreted as a robotic behavior.
5. Make sure your internet is secured i.e. you are not using any proxy or poor quality VPN. If you have any such protocol installed, kindly remove them and use your genuine IP and DNS servers.
If you've switched to your own IP and DNS server but still frequently getting the CAPTCHA prompt,
A. Reboot your modem/router
B. Release/renew your connections and flush DNS (not recommended to try without prior understanding of these functions).
Windows:
Go to Command Prompt and run following commands one by one:
ipconfig /flushdns
ipconfig /release
ipconfig /renew
Mac:
Turn off and on the network connections from System Preference. Based on your Mac version run the following command in Terminal to flushdns:
sudo killall -HUP mDNSResponder
Or,
sudo killall -HUP mDNSResponder
Or,
sudo dscacheutil -flushcache
Linux:
Reset the network connections and use following command on terminal to flushdns:
sudo /etc/init.d/networking restart
Note: If you are not sure about these commands or don't understand the functionalities kindly contact your System Administrator.