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Database Connection Error in Measurement & Automation Explorer (NI MAX)

Updated Apr 29, 2024

Reported In


  • Measurement and Automation Explorer (MAX)

Issue Details

I receive the following error when I start NI Measurement and Automation Explorer (NI MAX) or when I try to view my devices and software:

MAX Database Connection Error:
There was a problem connecting to the database. 
Please restart your computer and contact National Instruments if the problem persists. 



This error is associated with multiple root causes which are outlined below:

Note: Take into consideration that the majority -if not all - of these procedures require the user to have Admin Rights in the machine or explicit privileges to install, configure services and/or change registries. If you do not have Admin Rights, get in contact with your IT Administrator so they can either, grant you temporary Admin Rights or help you with the troubleshooting.
  • Firewall Settings
Removing MAX and all other NI applications from the blocked programs list is necessary for proper functionality. Some commonly blocked NI programs are: NIMax.exe, nimxs.exe, NiAsstnt.exe, nipalsm.exe, nidevmon.exe. This simple solution should be one of the first options explored when a database connection issue is seen in MAX - prior to uninstalling NI software.

NOD32 Anti-virus software could be blocking the HTTP port that MAX uses for the database. Please see: Why Do I Get "MAX Database Connection Error" When Using NOD32 Anti-Virus Software? .
  • NI Configuration Manager or NI Device Loader (nidevldu) Services Not Started
To verify if the NI Configuration Manager service is started and operating, go to Control Panel»Administrative Tools»Services. Scroll down to NI Configuration Manager (may show up as nidevldu).  You may also launch Services by navigating to Start»Run and entering services.msc.

If the NI Configuration Manager service does not appear in the list or has problems starting, the first thing to try is a Repair of MAX.

Make sure the service's Status is started. If it is not, right-click it and select Start. Also, try restarting the NI Device Loader service. For these changes to take effect, close out of Administrative Tools, and restart MAX. If the NI Configuration Manager or nidevldu service was not started before, MAX should now be able to operate correctly.
  • Disconnected ENET Device
If you previously had configured a Serial or GPIB-ENET device but this device is no longer connected, the server may experience some delays due to the timeout that occurs while trying to connect to the non-existent device(s).Due to the delay, MAX may report a Database Connection error. In this case, reconnecting the ENET device to the system or removing the reference to the ENET device will resolve this error. When switching between a Macintosh to a PC, you will need to reset the device to have it accessible.
  • Database Corruption
This error can also be caused by MAX database corruption. To remove MAX database corruption, you can reset the MAX Configuration Database
  • PCI-7041 Driver Combination
If you have the following combination of software installed you can change your registry or change the software you have installed. 
  • NI-VISA 4.x
  • PXI Platform Services 2.3
  • PCI-7041 RT Plug-In Board driver (Nov 2005 and earlier Driver CD)
  • NI-VXI
  • Traditional NI-DAQ (Legacy) 7.x
  • Driver corruption
           This error can be due to a corruption during the installation process, force reinstalling the driver will fix the corruption and solve this error.

Additional Information

MAX is divided into a front-end GUI (nimax.exe) and a back-end database service (nimxs.exe). This error is related to the method by which these front and back ends communicate with each other. MAX 4.1 performed this communication through TCP sockets. In previous and later versions of MAX, this communication was and is performed through shared memory. Additional NI services may still be using TCP for communication, so firewalls can still be the cause of this issue.

Because of this TCP communication, many firewall and internet security programs, such as McAfee Personal Firewall and Symantec Client Firewall, put MAX into a blocked programs list, which prevents it from establishing a connection to its database. In general, disabling the firewall will still leave MAX blocked from communication.

Most of our drivers, if not all, install NI-MAX. to determine if there is a corruption on the driver that may be causing this issue. If the solution steps shared above do not solve this issue, please contact NI Support.