[Thomas Specter Moderator September 15, 2020 at 8:48 am Thomas Specter Moderator]

Hi,

Thank you for reaching out to us.

Kindly ensure that you upload the same CSR which was downloaded via Hexnode -> Admin -> APNs. This error shall occur if by chance a wrong CSR file is uploaded instead of the one found in your Hexnode account.

This error could also occur when the downloaded file was opened and a change was accidentally affected on it prior to uploading it. Kindly ensure to keep the file un-edited while downloading and uploading to the APNs console.

Please have a look at this below help document for more info in the same.
https://www.hexnode.com/mobile-device-management/help/renew-apns-certificate/

We are available to be reached out at mdm-support@hexnode.com, should you need more support on the same.

Cheers!
Thomas Specter
Hexnode MDM