VirtuCache plugin showing ‘Error expanding plug-in zip’ and/or ‘Error downloading plug-in’

In vCenter 6.7 HTML5 GUI, if you see ‘Virtunet Systems VirtuCache 2.0 Plugin’ in Administration > Solutions > Client Plug-Ins as failed, and its accompanied by one or both of the below errors.

‘Error expanding plugin-zip. Make sure its a valid zip file. java.util.zip.zipException : error in opening zip file. java.util.zip.ZipFile.open(NativeMethod)’

‘Error downloading plug-in. Unsecure plug-in download over HTTP was blocked because the current webclient properties configuration does not allow it.’

These errors are not serious and don’t affect any VirtuCache functionality. They occur because you have upgraded vCenter to 6.7, and you were earlier using either VirtuCache Flash plug-in to VMware’s Flash based vClient or the older VirtuCache .NET plug-in to VMware’s .NET (thick) client. And VMware’s HTML5 vClient rejects older plugins that came over during the upgrade.

To fix these errors, follow the below steps to delete all the VirtuCache plug-ins within vCenter and re-register the VirtuCache plugin afresh.

Goto https://vcenter IP address/mob

enter vcenter credentials
then click on ‘content’ hyperlink in the line that says
Content | ServiceContent | content

Then click on ‘ExtensionManager’ in the line that says
extensionManager | ManagedObjectReference:ExtensionManager | ExtensionManager

Then in the ‘Properties’ box, you will see ‘extensionList’, and in that list, you will see three VirtuCache plugins.
extensionList[“com.virtunetsystems.vnx2.vsphere_6dot7_plugin”]    Extension
extensionList[“com.virtunetsystems.vnx2.vsphere_windows_client_plugin”]    Extension
extensionList[“com.virtunetsystems.vnx2ui”]    Extension

In the same screen, in the ‘Methods’ box, click on ‘UnregisterExtension’

Then enter the plugin names as shown below. Enter only one plugin name at a time in the ‘UnregisterExtension’ box, and click ‘Invoke Method’ hyperlink. It will return message ‘Method Invocation Result: void’, which means that the plugin has been removed.

com.virtunetsystems.vnx2.vsphere_6dot7_plugin

com.virtunetsystems.vnx2.vsphere_windows_client_plugin

com.virtunetsystems.vnx2ui

Refresh the ‘ExtensionManager’ web page that was showing those plugin extensions and now you shouldn’t see those plugins anymore.

Now re-register the VirtuCache plugin by going to the VirtuCache Web GUI and clicking on the ‘Register Plug-in’ button on the top left.