Hello Peter, version 4.3.0 is quite old (4 years...), and I am afraid it is not really possible to support it any more. If your ATENA maintenance is expired, and you can not use the current 5.1.x or 5.3.x versions, you might at least be able to update to 4.3.1g (the upgrade installer is still available from our web; write us your ATENA User ID - WR if you wish us to check if you are eligible before you download and install the upgrade).
I remember some time ago, there were some problems with the FORTRAN DLLs resulting in similar behaviour - do you have some other program using Intel FORTRAN (DIANA, ABAQUS, ...) installed on the same computer?
Have you alredy tried to save the ATENA Input File (.inp) from ATENA 3D and start the analysis using AtenaConsole? That way, you may be able to at least receive some error/warning message suggesting the problem source.
For more information on running analysis using AtenaConsole, please see ATENA Troubleshooting, 4.3.1 I have an ATENA Input File (.inp), how can I start the analysis in AtenaWin or AtenaConsole or ATENA Studio?; the latest version of the document is available from our web under Products - ATENA - Documentation.
Best regards,
Dobromil