Change the cryptoapicert SUBJ

Open       C:\Program Files\OpenVPN\config\config.ovpn   or       C:\Program Files(x86)\ OpenVPN\config\config.ovpn and change the line that says

cryptoapicert “SUBJ:”

to

cryptoapicert “SUBJ:username”

. . . replace username by the user’s actual username.

This helps specifying which certificate OpenVPN should use in case certificates have a naming conflict.