When this issue occurs, you receive the following message:
Call could not be put on hold
This issue occurs in the following scenarios:
Media bypass for the Enterprise Voice infrastructure is enabled.
The call is routed to a public switched telephone network (PSTN) through version 8.x of Cisco Unified Communications Manager (CUCM) or an earlier version of CUCM.
To resolve this issue, install the October 2014 update for Lync 2013 (KB2889929).
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