We are also facing this issue when trying to run multiple Eggplant Functional sessions on a Windows server. It seems to be a known problem with the ABBY FineReader component. Contacting Eggplant support has not proven helpful for now.
The only workaround at the moment seems to be to run Eggplant Functional in a sandbox, that redirects all disk IO of EPF to a session-specific folder and thereby avoids concurrent access to the same location. 