Dear respected members

i had the project delivered to clients.

with TP1500 comfort panel 6AV2124-0QC02-0AX0 

After about 3 years they called me and told me that they can't log in to the HMI by the user accounts. 

i also went to the plant and confirmed that.

My Question is why the HMI looses the users Account i did not set any password ageing.

Thank you in Advance.

Hi RUN Industrial Automation,

This occurs because the number of login attempts for a user or users has been exceeded. Once passed, there is no choice but to download the program to the HMI again or upload a backup of the users, if they have a copy made from the prosave. To prevent this from happening, you can change the number of attempts in the project.

Thank you All,

I was curious to know the reson ,  i solved the problem by reloading the HMI .

With the help of your advice, i just figured out that Limit for logon attampts is enabled in Runtime setting and default number of incorrect attempsts is 3.

Thank you Again!