If your Mac is crashing trying to use the network, see Turn off packet signing for SMB 2 and SMB 3 connections. It might help according to some users.
When you use an SMB 2 or SMB 3 connection, packet signing is turned on by default. You might want to turn off packet signing if:
- Performance decreases when you connect to a third-party server.
- You can’t connect to a server that doesn’t support packet signing.
- You can’t connect a third-party device to your macOS SMB server.
If you turn off packet signing, you lower the security of the SMB connection. Turn off packet signing only if both the client and server are on a secure network.
The issue apparently crashes some users computers. See the discussion in MacOS High Sierra 10.13.2 causing Finder crash. MPG cannot confirm if these crashes are fixed by the above, but Finder copies have been increasingly unstable, so it might just be general bugginess that increases with every release of macOS.
Speaking for myself—I cannot use netorking any more. At least not in any useful way. It takes 30-60 seconds just to find another machine on the same gigabit switch—awesomely slow. Some time ago (not sure when), Apple introduced a bug in Sierra that reduces performance by a factor of 10X to 100X. I’ve tried several times, checked that it’s gigabit on both ends, etc—I gave up. I now have to copy files to a drive and attach the drive to the other machine, then copy files off.