acrmartin,
This issue has been documented in knowledge base articles on our website, but the solution varies depending upon the hardware in use. What NI hardware and programming environments are you using?
Essentially, this error occurs when a function being called is not available in the dll file. Can you isolate the particular function being called when this error occurs? The most likely solution is a re-install of the drivers. In some cases it is necessary to manually select portions of the driver that are normally only installed when certain programming environments are installed. For example, if CVI is not installed on your system, certain driver functionality may not be installed by default.
The following link is to a knowledge base article that pertains to a different driver. However, the steps outlined in it are similar to what may be necessary to solve your problem. Click this link to check it out:
http://digital.ni.com/public.nsf/websearch/B53F3D5ADCFF287B86256869006EF6A9?OpenDocument
If this doesn't work out, post the answers to my questions and we'll troubleshoot from there. Thanks!
Elijah Kerry
NI Director, Software Community