Sometimes when processing the orders the system raise the error message "Method not found: '!!0[] System.Array.Empty()". This occurs because of the .NET framework mismatch.
Please install the .NET Framework version 4.6 or above.
Currently TOE has .NET framework 4.7.1 . So it is recommended to check whether the customer too has the same version on their machine. If not install it.
How to determine which .NET framework installed in your machine:
Install .NET Framework 4.7.1
https://www.microsoft.com/en-us/download/details.aspx?id=56116
Please contact The Order Exchange Support if there are more issues regarding this.