Hi Chris, I’ve been having this exact same problem too.
Turns out that Verisign’s ‘Subject’ in the class 1 certificate is over 256 characters in my case, and Notes doesn’t support this.
An enhancement request(SPR # EHET5XBSY6 ) has been made to add a warning message when Notes is importing this kind of certificate.
There’s a lot of rubbish in there that’s probably unnecessary. A Thawte certificate has only 2 lines, and works, so I’ll be using that unless Verisign get back to me with a certificate that works.
example:
E = nathanchandler@myorg.com.au
CN = Nathan Chandler
OU = Digital ID Class 1
OU = Persona Not Validated
OU = Member, VeriSign Trust Network
OU = Authenticated by VeriSign Australia Limited
OU = Terms of use at www.verisign.com.au/rpa (c)02