NotImplemented exception on Mono

[tiljanssen]

I have upgraded our packages from 2.6.0 to 2.15.0 and I now get a not-implemented exception on Mono on System.IdentityModel.Tokens.RsaSecurityToken.get_SecurityKeys. We are operating under a rather old version of mono (4.2), that we cannot upgrade at this point, but if I look at the current mono code in github, this function is still not implemented.

Do you have any suggestions on how to deal with this?

[brockallen]

I'd say to either stay on an old/working version, or ask whoever runs Mono why they don't support those APIs.