Unable to Access Yahoo Mail Account – Invalid Credential

Summary: Yahoo Mail Application is mainly used for sending and receiving emails but many users use it for storing contacts, scheduling meetings and managing calendars. But when they want to create a backup of Yahoo emails they need a third party application and without a third-party application, you cannot download Yahoo emails into PC.

So being a top-notch software company we provided Yahoo Backup tool to one of our customers to save the emails in the computer system as a PDF file with all attachments. But he was facing some kind of error when he tried to login into the software.


“Hi Sysinfo Team, I am your potential customer since 7 years. Recently I have purchased your Yahoo Backup Tool to save my yahoo emails as PDF with all attachments into my hard drive. But when I launched the software and enter my credentials, an error message popped up and I was unable to access your tool. Kindly help me out because my Yahoo Mail server is full and I want to create some on it. If it becomes overloaded with emails then I feel the chances of corruption are high. So kindly suggest me a way out so that I can backup Yahoo emails into my PC and delete them from the server. I have added a screenshot of the error which I have faced while using Yahoo Backup tool”

Screenshot Given by our Customer

Invalid Credentials

Type of Error- Invalid Credentials


In the context with this error, we gave him some solutions which proved helpful to him and finally, he was able to login successfully with his Yahoo Account into our software.

Tip 1- Rectify Your Credentials

It often happens that a user enters the credentials of another email account and therefore this error occurs. So before entering the credentials, you must make sure that you are typing the correct credentials which are related to the same email application. You must also enter the accurate email Address and don’t forget any character either from the email Address or password. If any character is missed out from the Email or Password then the software will show invalid credentials.

Tip 2- Disable Two-Step Verification

  • Login your Yahoo Mail Account from the official Website.
  • Go to Account Security option.
    Account Security
  • Disable Two-Step Verification option.
    Two-Step Verification
  • Enter the Registered Mobile Number to receive a verification message.
    Registered Mobile Number
  • Type the verification code you have received on your registered mobile number.
    verification code

Once you verify your account, the two-step verification setting gets disabled.

Tip 3- Turn on Less Secured Apps

  • Sign in your Yahoo Mail Account.
  • Go to Account Security.
    Account Security
  • Enable Allow apps that use less secure sign-in option.
    Allow apps

Once you are done with all the three Tips then try to login into our software and we hope that now you’ll not face any kind of credential errors.


Before you use our Yahoo Backup Tool, make sure that you are entering the right credentials and have disabled the two-step verification. You have to enable less secure apps settings for smooth Yahoo email conversion. I hope now you are able to access our software and can make the various conversions. If in case you have any confusion then you can contact our Live Chat Support Live Chat Support Team.