Swipe between pages doesn't work and unable two fingers scrolling up/down
What worked as well for me was switching off two finger swipe from the trackpad settings ('Swipe between pages' setting), then turning it on again directly after. A lot more convenient than logging out and in again.



If the problem happens too often a PRAM reset often helps as well:


Shut down your Mac. 
Locate the following keys on the keyboard:
Command (⌘), Option, P, and R. You will need to hold these keys down
simultaneously in step 4. 
Turn on the computer. 
Press and hold the
Command-Option-P-R keys before the gray screen appears. Hold the
keys down until the computer restarts and you hear the startup sound
for the second time. 
Release the keys.