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I just received this error message from the web site of my Bank. And to clarify, I only have an account in that bank, I don't own the whole bank.

So what happened and how can this be fixed?

I had to fill a form where it asked for "mobile number" of my accountant. I only have her office number, but I thought let's give that a try. I saw two fields one was a selection field that allowed me to select the area code the other one was to type in the number.

The list of area codes included both the mobile area codes and the area codes of the various localities. So I thought apparently even though they wrote "mobile number" they would accept a fixed phone number as well.

Clicking on submit gave me that exact, but for a user confusing and totally useless error message.

I am trying to guess here what's really going on in the company. What made it possible to reach such an error message? More importantly, how can an organization prevent such errors and how can it monitor the system to notice when such errors do apper to users.

How do you try to prvent such situations?

What do you do to recognized such situations so you can fix them?