EMD upload error: uploadXMLFiles skipped :: OMS version not checked yet..

Due to communication between OMS and agent does not work. This is in most cases because something has been changed to one of the components so the SSL certificate is not valid anymore. Therefore you have to resecure the agent. Your last try shows the error that you have used the wrong password for registration
Then go to the agent and do the following:
- emctl stop agent
- delete all files in
$AGENT_HOME/sysman/emd
rm agntstmp.txt
$AGENT_HOME/sysman/emd/upload and
rm -rf *
$AGENT_HOME/sysman/emd/state
rm -rf *
- emctl clearstate agent (this should delete all state files but sometimes it is not enough, but I experienced that it is better to use this command after deletion of the files)
- emctl secure agent (and specify the password on demand)
- emctl start agent

This should solve your problem.

Incase if you still have any issues in starting the agent or uploading files is not getting processed then look into the below:

Login to EM Console --> Setup -->Agents  -->

Misconfiguration Alerts and Blocked Agents

and check whether the server is blocked or not if it is blocked unblock it and then try the below:

./emctl clearstate agent
./emctl upload agent
./emctl status agent