When I send out an email invitation, either from Linux or Windows, the included key can't be imported on Windows (but works on Linux).
Steps to reproduce:
1) Select "Enter the certificate manually"
2) Paste the key into the lower pane, I get a green check mark
3) Click "Next"
I then see the following error message:
"Certificate load failed:
Unknown section type found (Certificate might be corrupted)."
OTOH, when I export my key to an ASCII armored file and send that, it can be imported just fine. That's what the ASCII armored format has been created for, to send keys via email.
My RS version on Windows is 0.5.5c 7067 (7068 on Linux).
Please send out the invitation email with a key in ASCII armored format, since this is known to work everywhere.
Seems to fail only when the used key has been created with GPG and then imported into RS.