Temporary glitches or minor bugs in the app or phone can sometimes cause login issues. Restarting clears the app's memory and refreshes the phone's system, potentially fixing the glitch. So, initially, restart the app even if the issue persists. Then restart/reboot your mobile phone by pressing the Power button (right picture) for Android, and the Power button and Volume Up button (left picture) for iPhone. Log in to your Snapchat after restarting your device to check if the C14a issue is gone.
Read More : https://guideet.com/snapchat-code-c14a/