This hot fix can be downloaded from the SFDC Customer Portal Web UI, using your username and password for support.tibco.com.  Once logged on you can find the hotfix under Download Menu :
AvailableDownloads/BusinessWorks/Plugins/REST_JSON/2.1.0/hotfix-03

Listed below is a summary of updates included. Please refer to the associated read me document for any additional information.

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Closed Issues in 2.1.0_HF-003 (This Release)

Defect ID: REST-1262

    REST Dispatch and Reply activity threw Null Pointer Exception when receiving 
    HTTP request URL without resource URI. 

Defect ID: REST-1494

    REST JSON plugin 2.1.0 lost Proxy functionality for Invoke REST API activity.

Defect ID: REST-1511

    REST JSON plugin 2.1.0 did not allow JSON string in Query parameter for 
    Invoke REST API activity.

Defect ID: REST-1513

    REST Dispatch and Reply activity threw inappropriate error code 404 for 
    missing mandatory parameters, it should be 400.

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