Whenever I use
pmset sleepnow in Terminal (even with
sudo) I get this error:
Unable to sleep system: error 0xe00002e2. I have no idea what's going on. Please help!
I struggled with the problem for months without any luck; the computer was unable to sleep, the sleep option on the apple menu was greyed out, pmset -g assertions (the most popular suggested solution to find ongoing processes) didn't return any result, and resetting the SMC didn't work. Today I finally found the solution that worked for mine
sudo pmset -a disablesleep 0
Hope this works for others too!