NAV 2013 & Later - An item with the same key has already been added.

Dear All,

During a upgrade process to NAV 2013 R2 from NAV 2009 SP1, i faced an issue which took a lot of time to resolve.

So i thought sharing the same with you all.

When i tired to run a page it crash the NAV 2013 Windows Client exe, I thought that page might have issues but when i run table from developer environment everything same.

The ERROR that i was getting - "An item with the same key has already been added"

Below is the Some part of Error in event viewer -

System.ArgumentException was unhandled
  HResult=-2147024809
  Message=An item with the same key has already been added.
  Source=mscorlib


Findings -
I started finding it on Google and found one of the two relevant article -

Article 1 - From Microsoft Blog specifying that the issue was resolved in NAV 2009 R2 with a Exe Fix.

Article 2 - From Microsoft Dynamics AX Blogger who specified that they have same error when they Run a Report in AX. The Reason they specified that in Report there are two fields in Report with same Name.

Analysis -

I started finding same field name in tables with same name or caption. "NOTHING Found"

Result -
Finally i found that there are multiple keys with same fields.

So if you face any issues look for duplicate keys...

Enjoy...

Regards,
Saurav Dhyani