error on lom-interface SSL certificate upload on Checkpoint 4800

[a574591]

Hello,

As I am not sure if this is the right location, it probably is not...

I wanted to replace the ssl certificate on the lom-interfaces of several devices. I have ready certificates with .pem format and the private key.
When I try to upload the certificates on the 4800 devices which run the 2.8 firmware, I only get one file to upload which gets the error: "Certificate upload failed. Cannot validate." - which I also experienced with other devices with outdated firmware.
In other devices it is a place to upload the certificate and the private key separately and type in the pre-shared key. Here there is only one file to be uploaded. Is it possible to combine the private key with the certificate file together to have this right?

When trying to generate the certificate on the device I get to downlowad the csr.txt but it is no use to upload it as certificate.

Can you advise anything here?

Is it possible to upload other firmware than the 2.8 for the 4800 (like the 3.46 for the 5400 series), to solve this issue?
I know that the devices are already out of support (or soon will be) and will be replaced this year or next, but maybe there is a chance that there is an easy fix for this issue.

[PhoneBoy]

I believe you can combine the certificates, yes.
In terms of upgrading the LOM firmware beyond the recommended version, I would check with TAC: https://help.checkpoint.com