CRRTC8500E: Server Error: Unable to resolve the planning attribute 'com.ibm.team.apt.attributes._com.ibm.team.apt.attribute.complexity opening workitem from VS client.

Since the problem is with attribute mapping, open the the project configuration page in RTC Eclipse client go to "Process Configuration" tab and check the mapping of the attributes under "Project Configuration->Configuration Data->Planning->Plan Attributes"
Check how the  attribute "com.ibm.team.apt.attributes._com.ibm.team.apt.attribute.complexity" is mapped and correct the mapping if needed.
Looks like mapping got modified to a invalid state.

Hi,

I am facing the same issue in RTC V5.0.2, Request you to please elaborate the solution. I am unable to map the attributes

Thanks in advance,

Vijay

The mapping needs to be checked in the process template for the attribute which the error is complaining about.
403 we started to read plan attribute mappings as well and if the mapping is incorrectly done then you will get an error in VS client.
Check how the error attribute is configured.

If you can not figure out how to map attributes , perhaps you can attach the details of the error

The process template code that you need to verify :

 <attribute id="com.ibm.team.apt.attributes._com.ibm.team.apt.attribute.complexity" implementation="com.ibm.team.apt.client.WorkItemAttribute" internal="false" name="Story Points" readOnly="false">
                    <parameters>
                        <parameter key="attribute" value="com.ibm.team.apt.attribute.complexity"/>
                    </parameters>
                </attribute>