Clarify error messages for unified routing toggle

Added specific error messages related to unified routing provisioning failures.

Author: neeranelli

support/dynamics-365/customer-service/unified-routing/troubleshoot-enabling-unified-routing.md

@@ -16,7 +16,11 @@ This article provides a resolution for the issue where provisioning of unified r
 
 ## Symptoms
 
-When you attempt to turn on the unified routing toggle, an error message appears. 
+When you attempt to turn on the unified routing toggle, one of the following error messages appears:
+
+- "Unified routing provisioning failed due to issues in configuration..."
+- "Unified routing provisioning failed due to an error in deactivation of basic routing rulesets..."
+- "Unified routing provisioning failed due to an error in activation of basic routing rulesets..."
 
 ## Cause 1
 
@@ -47,4 +51,4 @@ The system creates a master entity routing configuration for the Case table as p
 
 ### Related information
 
-[Enable unified routing in Dynamics 365 Customer Service](/dynamics365/customer-service/administer/provision-unified-routing)  
+[Enable unified routing in Dynamics 365 Customer Service](/dynamics365/customer-service/administer/provision-unified-routing)