[Plugin : Google XML Sitemap Generator] Error Rebuild Sitemap automatic

i have error in plugin google xml sitemap generator

Your sitemap is being refreshed at the moment. Depending on your blog size this might take some time! Due to limitations of the WordPress scheduler, it might take another 60 seconds until the build process is actually started.

and i wait until one day this message still appears
please help me please help me to fix the this error

https://www.ads-software.com/extend/plugins/google-sitemap-generator/