If you are receiving the error message:

Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx).

System.FormatException: Guid should contain 32 digits with 4 dashes (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx).
at System.Guid..ctor(String g)
at finawareStockControl.mainform.RepricerWorker_RunWorkerCompleted(Object sender, RunWorkerCompletedEventArgs e)
at System.ComponentModel.BackgroundWorker.OnRunWorkerCompleted(RunWorkerCompletedEventArgs e)
at System.ComponentModel.BackgroundWorker.AsyncOperationCompleted(Object arg)

This means that you are missing the token registry key. Perform the following actions which will clear the registry keys, and re-instate them, including the missing token key.

* Open Linnworks

* Click on the button with the link symbol in the top left hand corner of the screen, next to the Advisor button

* Click Disconnect

* Re-open Linnworks and follow the instructions for logging back in.

* Restart the PC