transferring info from old Mac to new Mac

Do you have a Time Machine backup to Restore to/from?

Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode? Could take 10 minutes.

Safe mode attempts to repair Disks & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions, so if Safe Mode works try again in regular boot.

To find out if it's system wide or user specific, try this...

Open System Preferences>Users & Groups, unlock the lock, click on the little plus icon, make a new admin account, log out & into the new account.

Does those work in the new account?

You should not use wireless to do a transfer. It is too much data for that slower method. Use a USB cable to connect both computers for doing a transfer.

Have heard of that one, have you run Disk Utility's First Aid on both drives?

Which method are you using to transfer?