VISA not working with LabVIEW x64

[PierreCottin]

Hi,

I have a setup consisting in a PC running Win7 x64, LabVIEW 2014 x64, a RS232 instrument, and NI-VISA for the communication. It used to work well but for some reasons I recently got the following error message (-1073807202) when trying to open the COM port:

LabVIEW:  (Hex 0xBFFF009E) VISA or a code library required by VISA could not be located or loaded.  This is usually due to a required driver not being installed on the system.

I have tried to completely uninstall NI-VISA and install the latest version (17.0) including support for 32b and 64b. However, I still get the same error. When running LabVIEW 2014 x86, no error, it's working. Same results with MAX.

When I install NI-VISA, the default location is C:\Program File (x86)\National Instruments. I have tried to install it in C:\Program Files\National Instruments instead but the installer refuses because of "incompatible product installed" in the directory.

I have check the content of Windows\System32 and there are visa32.dll, visa64.dll, visaConfMgr.dll, visaUtilities.dll

In Windows\SysWOW64: VISA_Shared_CleanupUtility.exe, visa32.dll, visaConfMgr.dll.

Any suggestion would be welcome.

Thanks.

Pierre

[JÞB]

You may be missing a service pack

[Chase.E]

Have you let VISA install itself to the default directory before you had this error?

[PierreCottin]

Actually, I do not have the choice: it has to be in the default directory (C:\Program Files (x86)\National)

[JÞB]

The latest several versions of NI VISA use SHA-2 signing.  Unless you have applied the Microsoft patch I linked to earlier (Which adds SHA-2 signing) it will not work correctly.  

[PierreCottin]

Finally, I managed to make it work. Instead of trying to install the latest version of VISA, I got back to the original LabVIEW 2014 Driver DVD and installed VISA from this DVD. Now, both x86 and x64 versions are working well.

I did not have the chance to try the service pack you propose. I will keep it in mind for the next time.

Thanks.