Foreword: Simply record the problems encountered. Although there are solutions on the Internet, you should keep them for yourself
When upgrading Wordpress, Wordpress will_ Add core in the options table_ Updater.lock record.
If you interrupt the Wordpress upgrade halfway, such as closing the current page and refreshing the page, this record will be generated in the database.
When Wordpress detects the existence of this record during the next upgrade, it will return "Another update is in progress".
Manually delete wp_ Core in the options table_ Updater.lock record
Or execute the SQL statement: delete from wp_ options where option_ name='core_ updater.lock';