I came-up with the same error.
After i run sh /scripts/update_cwp in SSH, i noticed that the timeszone format was incorrect.
Then, i go to "WHM" of CWP and "Server Config > Change Date & Time" and there you have (Don't forget to change /usr/local/php/php.ini and /usr/local/cwp/php71/php.ini timezone ("date.timezone" field))
Click on each link and search to find "date.timezone" and comment it with ";" in front of it (without the ") . After that, click save and restart the server and for me it worked.
I think, when changing the timezone, we should have a list with the correct format of the timezones for those files.