Invalid CRC means you are losing packets due to an invalid checksum (CRC)
This is normally caused by a defective LAN-adapter, a cabling problem or other problems with your physical layer. If you know when these errors have started to appear, think wheter the last modification to your network coincides with this. Then you have a starting point, otherwise you will have to follow the rigourous method:
When the count continues to rise steadyly, try to locate the interface thats causing the errors as follows. Try disconnecting them one by one until the errors stop to increment and check the cabling from there on.
No need to tell you that your users will be disconnected also, but this type of error is often only reproduceable during office hours when all network nodes are active.
Goodluck!
