Code 31 in Windows Device Manager While Using a MXI Connection

Solution

First complete the steps in the MXI(e) Connectivity and Troubleshooting Guide .
Second, take note of the location of the error and what PCI Bus it's using, and what slot. In the example above it's in slot 5 of the computer and using PCI bus 43
Run the tool in Determining the Range and Number of PCI/PCIe Root Bus Devices , to find the range of buses the computer has. Convert the range from hexadecimal to decimal and determine if the bus, or partition of buses that the card is using has enough resources for the setup

Figure 2: Example Root Bus Partition

In the above example, the PCIe card is on Root Bus Partition 2 since the PCIe bus is using 43, and 43 is between 20 (32) and 2b (43), but since this partition only has 10 resources, a 20 resource setup can't be used, which can be estimated here.
Try ALL slots with and without the BIOS compatibility (including graphics card slots) to get on a different partition. These partitions often can't be changed or reallocated.
Consult with the motherboard manufacturer to check if there's a BIOS setting that could change the root bus partitions and which PCIe slots correspond to which partitions in the different configurations.