HPE Officeconnect 1950 48G SFP+ Port is down

Hello all together,

i bought 2 HPE 1950 48G Officeconnect Switches to Connect 2 Buildings via 10G SFP+.
On the first of both, the link is up. On the second the link is down. On both Switches, the Switch detect the sfp+ -Adapter. I try to enable the Interface but its seconds later off again.

Has anybody any suggestions for a managed switch newbie?

Thanks