Keyboard: (Beta 1) Telex keyboard causes Safari to freeze and causes Command key to fail
Login Window: (Beta

Unexpected logouts when logging in
Preview: (Beta

Blurry PDF rendering
Power: (Beta 1) Some devices may fail to wake correctly
System Preferences: (Beta 1) Auto-brightness toggle doesn’t persist after a reboot on some devices
Today View: (Beta 7) Now Playing widget doesn't update correctly
System takes longer to boot (rMBP 2015)
Samba connections broken (extremely slow)
Attempts to create time machine backup fails, no backups possible
Can't disable Time Machine local snapshots (via terminal)
Can't hide login items in system preferences
Problems with network (HTTP; sometimes webpages load very slowly)
random restarts (Mac Pro, 2013)
slow UI animations (rMBP 2013, 13")
„telnet“ command not present in terminal
System hangs when locking screen and resuming it on again
reboots when using key shortcut to put to sleep mode
high battery drain when in sleep mode
Randomly switching color mode when playing movies (for some - not confirmed)
after reboot auto brightness is always turned on
external display is not detected when it's connected to the device at boot up (for some - not confirmed)
Printing fails with "Filter Error". Reinstalling printer did not fix.
Safari "download tab" doesn't resize appropriately
Mails app crashes frequently
zooming pdfs in Safari with touchpad gesture results also in scrolling up
Overall system slowness
Can’t zoom out of pdf in preview
exporting edited pictures in photos might create a corrupted picture
iMessages is broken after rolling back Sierra, contacts show as numbers and unable to send iMessages to new contact as says number not registered to iMessage.
MacBook (Pro/Air) Battery works, but is not seen. In Powersettings if turned on it closes instantly (probably only 3th party batteries)
Mail Preference Panes not displaying correctly, only get blank window.
Launchpad - cannot delete app after icon starts wiggling when editing Launchpad
Auto-Unlock with Apple Watch not functioning. "Mac cannot communicate with Apple Watch"
Internal trackpad is not recognised in System Preferences (MacBook Mid 2010)
AVCHD content in browser view in QuickTime cannot be scrolled
AVCHD content in browser view in QuickTime cannot be scrolled
FaceTime (avconferenced process) crashes with Always on Top mode when entering background app in full-screen
Internal trackpad is not recognised in System Preferences (MacBook Mid 2010)
iOS 10 devices don't see tabs opened on Macs with Safari 11