This is the error I encountered while updating VoIP certificate on twilio Programmable Voice in dashboard:

An error was encountered while processing your submission.
There was a problem attempting to update your Push Credential: Could not parse certificate

The Solution

You need to copy the certificate and key including following lines

—–BEGIN CERTIFICATE—–

—–END CERTIFICATE—–

—–BEGIN RSA PRIVATE KEY—–

—–END RSA PRIVATE KEY—–

If you miss these lines then you will see this error.

This error may also occur if you have swapped private key and certificate so make sure that you care copying correct keys.