What did you do in the general settings? Did you change the URLs there to something else? If so, what to, and what were you intending to do with it?
i wanted to use the sub-domain i created in Hostgator to do another website, that’s all and i followed the tutorial of w.sculptor’s youtube video for an e-commerce website, but when i added my subdomain name i got this errror message and there was nothing i could do about it. My domain name is itmustbegac.com and the subdomain name is store.itmmustbegac.com The link to my site is https://itmustbegac.com/wp-admin
When you created the store subdomain, it broke itmustbegac.com, and you didn’t do anything in the Dashboard of itmustbegac.com?
i went to dashboard – settings – general – a new site title – a new tagline and then changed the URL on both WordPress Address and Site Address to my new subdomain http://store.itmustbegac.com. Thank you James for helping me because i am a bit lost!
Ok, that doesn’t create a new site, that’s just the first step in moving your site to a new location.
If you just want to create a new site, you need to first save the old site by changing the URLs back directly in the database: https://codex.ww.wp.xz.cn/Changing_The_Site_URL#Changing_the_URL_directly_in_the_database
Then, install a new WordPress blog at the subdomain.
If you did want to move the blog instead, you need to finish the move: https://codex.ww.wp.xz.cn/Moving_WordPress#Changing_Your_Domain_Name_and_URLs
as you adviced i went to hostgator, opened phpMyAdmin and now in order to ave the old site by changing back the old url. there is a window operation where it says rename database to (see my screenshot)