Challenge
Attempting to deploy the Veeam Plug-in for VMware vSphere Client through Veeam Backup Enterprise Manager fails with the error:
Error downloading plug-in. Make sure that the URL is reachable and the registered thumbprint is correct. Certificate doesn't support 'digitalSignature' KeyUsage
Cause
The certificate in use by Veeam Backup Enterprise Manager has a KeyUsage parameter defined, but the parameter Digital Signature is not specified.
Default Veeam Backup Enterprise Manager "Veeam Self-Signed Certificate" History
In Veeam Backup Enterprise Manager 10a and older, the self-signed certificate generated by the installer was created with the following:
KeyUsage: Key Encipherment, Data Encipherment
Starting in Veeam Backup Enterprise Manager 11, the self-signed certificate generated by the installer has no KeyUsage specified, meaning all uses are accepted.
This means that if a Veeam Backup Enterprise Manager deployment was initially installed with version 10a or earlier and then upgraded to newer versions using the same self-signed certificate, the issue will occur.
Solution
To resolve this issue, either generate a new Veeam self-signed certificate or import a new certificate you've generated, and then assign the new certificate to the site within IIS Manager.
More Information
If the Veeam Plug-in for VMware vSphere Client continues to have issues deploying, please create a Veeam Support case for assistance.
