Need help! PCI-E slot not working if I install another graphics card

Hyper 2U SYS-221H-TNR PCIe Slot Configuration Options Each expansion card slot is assigned to specific motherboard PCIe x8 MCIO connectors or PCIe x16 slots

From the System Utilities screen, select System Configuration > BIOSPlatform Configuration > Network Options > Network Boot Options > PCIe Slot Network

pciex16 slot * The PCIEX8 slot shares bandwidth with the PCIEX16 slot When the PCIEX8 slot is populated, the PCIEX16 slot will operate at up to x8 mode 1 x PCI Express

slot veranderen One half-height Gen 3 PCIe x16 slot; One half-height Gen 3 PCIe x1 slot SATA Two SATA slots for hard drive, slim optical drive One