The error following error may occur when you try to use one of the ExportParams objects in the Export() method with the Outproc Engine loading.
No known conversion for argument 3 from ‘COutprocSafePtr<I***ExportParams>’ to ‘IUnknown*’
The reason for this behavior is that the support for IUnknown/IDispatch interfaces has not yet been fully implemented in the FineReader Engine 12 for Linux.
In order to avoid the issue, please pass the corresponding value as 0. If you need to change the export parameters, use the custom user profile by adding your settings in the profile.ini file and loading it with the LoadProfile method.
Please get more helpful information in the Working with profiles section of the User's guide.