The following error is similar to the previous error except that the problem is not with an unfamiliar critical extension but with a value that pkg does not understand for an extension that pkg does understand.
pkg install: The certificate whose subject is /C=US/ST=California/L=Menlo Park/O=pkg5/CN=cs5_ch1_ta3/emailAddress=cs5_ch1_ta3 could not be verified because it has an extension with a value that pkg(5) does not understand. Extension name:keyUsage Extension value:Encipher Only
In this case, pkg understands the keyUsage extension, but does not understand the value Encipher Only. The error looks the same whether the extension in question is critical or not.
The solution, until pkg learns about the value in question, is to remove the value from the extension, or remove the extension entirely.