"An unexpected error has occurred" error on the HTML5 client when clicking on Update Manager tab

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• Update Manager 6.7 throws an error "An unexpected error has occurred"
• In /var/log/vmware/vsphere-ui/logs/vsphere_client_virgo.log:

[INFO ] tp-nio-127.0.0.1-5090-exec-5 com.vmware.vum.client.websocket.VumWebSocketEndpoint Websocket opened with session: 1d4
[INFO ] p-nio-127.0.0.1-5090-exec-14 com.vmware.vum.client.vc.VumVcServiceImpl Time for extracting VUM Extension info: 16.065161 ms.
[WARN ] p-nio-127.0.0.1-5090-exec-14 com.vmware.vum.client.remoting.impl.VumServiceImpl
Request failed java.lang.IllegalArgumentException: array element type mismatch
    at java.lang.reflect.Array.set(Native Method)
    at com.vmware.vim.vmomi.core.soap.impl.unmarshaller.ArrayStackContext.getValue(ArrayStackContext.java:92)
    at com.vmware.vim.vmomi.core.soap.impl.unmarshaller.UnmarshallerImpl$UnmarshallContext.unmarshall(UnmarshallerImpl.java:205

Environment

• vCenter Server 7.x

Resolution

1. Login to VCSA using putty/ssh session as root user.
2. Stop the vsphere-ui service using command
   • service-control --stop vsphere-ui
3. Rename the "work" folder for vsphere-ui using the below steps,
   • Use WinSCP and navigate to folder and rename the folder as well (additional option).
   • Or use the below command
     • mv /usr/lib/vmware-vsphere-ui/server/work /usr/lib/vmware-vsphere-ui/server/work_old
4. Restart vSphere Client service using below command
   • service-control --start vsphere-ui