2 . Some SPFs need configuration and actions to be able to work in a Catalyst 3850 switch (mostly when they are manufactured by third-party). Try following actions:
3850(config)# no errdisable detect cause gbic-invalid 3850(config)# service unsupported-transceiver
Remove SFP module, shutdown/no shutdown the port, insert back the SFP module.
3 . Take into consideration the following software defects:
CSCut94443 - GLC-SX-MMD is not recognized after OIR CSCuj31712 - certain Vendor Sfp force ports to err-disable upon OIR
It is recommended to go to stable version of code whether if you are hitting those bugs or not. The recommended version on cisco.com has helped to fix this kind of incidents. Following documents can be referred for this.