Unable to open business process in business central with update patch 1 (BPMS 6.2.1)

Issue

Since we have installed Red Hat JBoss BPM Suite 6.2 Update 1, we are having problems opening the business process perspective in business-central. When I click on any business process from the left menu, business central doesn't open the flow. Here are the steps in detail:

• Authoring >> Project Authoring >> Able to open business process successfully.
• Process Management >> Process Instances >> Opened a process instance and viewed the process model successfully
• Opened another process instance and tried to look at the process model, but it doesn't open the process model
• Went back to Project Authoring and tried opening the business process and it doesn't open