Looks like you didn't have Agent extension installed on the ePO server. Do you have? If yes then what is MA extension build (Menu->Software->Extensions).
Does this agent extension come with agent zip package or the VSE zip package?
No. You can download MA extension either from software manager or from download site. The file name will EpoAgentmeta.zip
I found the MA extension, but when i want to import it, i get the following error:
Cannot upgrade extension EPOAGENTMETA because an extension with that name is already present in a partially installed state. Remove the extension before attempting an upgrade.
When i check my extensions, i see that there's an unsigned extension indeed.
However, i can't remove it because i don't have a remove button, only a blank page at the right.
Is there a way to remove it?