Hi Symon,
With the error log, it seems that there might me more than one Hostagent on the system.
I would suggest you to uninstall hostagent completely along with the Users for that and Install a fresh host.
During the installation, keep a check of all the ports its taking and make sure they are all open.
You can also check your solman installation screenshots if you have taken and check the login user and external/internal ports.
Also check the permissions for the user on the installation directory. sometimes that is also a headache.
Hope this helps!!!
-AC