A user informs you that CAR queries are failing consistently for recent dates. However, older dates are still
accessible.
Which of the following is most likely the problem? (Select the best answer.)

A.
The Cisco CAR Web Service is not running.

B.
The UCM system is generating CDR files too slowly.

C.
The user does not have the privileges to log on to CAR.

D.
The CDR Enabled flag is set to FALSE.

E.
The disk space where reports are stored is full.

Explanation:
Of the choices provided, the problem is mostly likely that the CDR Enabled flag is set to FALSE if Cisco Call
Detail Records (CDR) Analysis and Reporting (CAR) queries are failing consistently for recent dates but older
dates are still accessible. If the CDR Enabled flag is not set to TRUE on a Cisco Unified Communications
Manager (UCM) server, CAR reports will not be generated for that server. In a UCM cluster, the CDR Enabled
flag should be set to TRUE on the Publisher server and on all Subscriber servers in the cluster. If the CDR
Enabled flag is already set to TRUE, you should verify that only the Publisher server has the Cisco CDR Insert
service activated. In addition, you should verify that the Call Diagnostics are enabled and that the Cisco CAR
Scheduler service is running on the Publisher server.
It is likely that the Cisco CAR Web Service is running if older dates are still accessible, even though CAR
queries are failing consistently for recent dates. CAR is typically accessed by using the Tools menu in Cisco
Unified Serviceability. If the CAR Web Service were not running, CAR would not be available from the Tools
menu. Thus the user would have no way of knowing whether recent queries were failing or whether older dates
were still accessible. To activate the CAR Web Service, click Tools > Service Activation in Cisco Unified
Serviceability, select the call processing server from the Servers dropdown menu, and then select the check
boxes next to the appropriate CDR services.
It is not likely that the UCM system is generating CDR files too slowly. By default, every UCM server can
generate one CDR file and one Call Management Records (CMR) file every minute for up to one hour. In
addition, it is not likely that the disk space where reports are stored is full. The oldest CDR files are deleted on
an hourly basis by the CDR Repository Manager’s File Manager process if disk usage reaches a maximum
threshold. Therefore, if the disk were full, older dates would be affected by the issue, not recent ones.
It is not likely that the user does not have the privileges to log on to CAR, because the user can see the results
of older queries. By default, any UCM user can be configured as a CAR administrator by adding the user to the
Standard CAR Admin Users group in UCM. This includes application users and end users.
However, application users cannot access the Individual Bill report even though they might have read and write
access to the CAR database.

https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-managercallmanager/68010-carfailure.html#solution