line protocol is down (err-disabled)

SWITCH#sh int G0/18
GigabitEthernet0/18 is down, line protocol is down (err-disabled)
Hardware is Gigabit Ethernet, address is 001f.7777.7777 (bia 7777.7777.7777)
Description SWITCH-A
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255255, txload 1255, rxload 1255
Encapsulation ARPA, loopback not set
Keepalive not set
Auto-duplex, Auto-speed, link type is auto, media type is unknown
input flow-control is off, output flow-control is unsupported
ARP type ARPA, ARP Timeout 040000
Last input never, output never, output hang never
Last clearing of show interface counters never
Input queue 07500 (sizemaxdropsflushes); Total output drops 0
Queueing strategy fifo
Output queue 040 (sizemax)
5 minute input rate 0 bitssec, 0 packetssec
5 minute output rate 0 bitssec, 0 packetssec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out


Produced logs:
%LINK-5-CHANGED: Interface GigabitEthernet0/18, changed state to administratively down
%GBIC_SECURITY_CRYPT-4-VN_DATA_CRC_ERROR: GBIC in port Gi0/18 has bad crc
%PM-4-ERR_DISABLE: gbic-invalid error detected on Gi0/18, putting Gi0/18 in err-disable state
%LINK-3-UPDOWN: Interface GigabitEthernet0/18, changed state to down



This could be associated with a problem in SFP.
Check if the SFP is correctly connected, and if it is a Cisco SFP!