By default, the SOAP handlers ignore underlying exceptions, and always return a generic "Service is not available" error message with error code –999 in the response model, if a SOAP connection to the OneSpan Authentication Server instance cannot be established.
To make error handling easier, you can change the behavior to re-throw underlying exceptions so they can be propagated to and properly handled by the application (as IdentikeyConnectionException).
Open the application configuration file (app.config) and set the following value to True:
<setting name="RethrowOnConnectionError" serializeAs="String">
<value>False</value>
</setting>