Application endpoint for Contact object cannot be created. The following exception was thrown during application endpoint ...

Application endpoint for Contact object cannot be created.

The following exception was thrown during application endpoint creation for Contact object '%1'. The Response Group associated with this endpoint will not be available.
Exception: %2
Inner Exception: %3

Cause: Networking problems with the Front End server, or Front End server configuration problems.
Resolution:
Check for eventual SIP errors on the Front End servers.

Anonymous users (also known as "anonymous participants") are external users who do not have credentials in Active Directory. ... Another Lync Server product with version PROPERTY_EXISTING_32BIT_PRODUCT_VERSION is already installed. Lync Server products ... Another Lync Server product with version PROPERTY_EXISTING_PRODUCT_VERSION is already installed. Lync Server products with ... AppDomain threw an exception. Assembly %1. Exception Details. %2 Cause: One of the applications identified in the eventlog ... Application endpoint for Contact object cannot be created. The following exception was thrown during application endpoint ... Application failed to register for change notification. Directory='%1'. Error Code: %2 Cause: Encountered a system error ... Application registration denied. Application Uri: '%1' Cause: Denied application registration as it is not enabled. Resolution: ... Application registration failure. Application Uri: '%1' Cause: Failed to register an application. It is configured with a ... Application registration failure. Application Uri: '%1' Cause: Failed to register an application. The application manifest ...