WordPress 4.5.1 is available and addresses a dozen items reported against WordPress 4.5. According to Adam Silverstein, “a singular class issue that broke sites based on the Twenty Eleven theme, an incompatibility between certain Chrome versions and the visual editor, and an Imagick bug that could break media uploads,” are among the bugs fixed. A detailed list of changes can be viewed here.
WordPress 4.5.1 is already being pushed out to sites configured for auto updates. If you’d rather not wait or have auto updates disabled, you can browse to Dashboard – Updates and click the Update Now button. If you encounter an issue or believe you’ve discovered a bug, please post it in the troubleshooting section of the support forums.