Could you please clarify, what version of Xeoma you are using? What is your OS? Does the client have the same version of Xeoma as the server?
Please make sure that the module
Preview and Archive is present in the chain and that it is enabled. If the module's symbol is not outlined in white, it is disabled.
If this doesn't help, please contact our support team, you can find the contact information here:
http://felenasoft.com/xeoma/en/contacts/