is it in problem.pkt file ?, not able to open this file in my PC, I will check after installing packet-tracer and get back to you.

In order to look into your issue, we need logical/physical topology and configuration.

Can you explain it with some more details, like what is the topology you are using.

When you configure port channel with two or more ports, it works as a single unit untill and unless there would be minimum one functional port. So one of the advantage of port channel is to provide link redundancy. Therefore if you want to include on...

Can you please check the tftpdnld command shows by typing help on rommon mode and if yes, please see your TFTP_FILE name, generally file ends with extension like .bin.