GUID should contain 32 digits

If you are calling a Store procedure that accepts GUID's as parameters, you will need to initialize those parameters to a valid GUID, before executing the ADO command.

This is the error you will find on the event log:

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

to solve this, you can either initialize the GUID to Empty:

GUID paramGUID = new GUID.Empty();

or set the parameter to the string:

GUID paramGUID = new GUID("00000000-0000-0000-0000-000000000000");