this error appears when i click start in mesh operation can i know how to solve it??
The message means exactly what it says. You can share the project with us in the comment section (simply paste the link) and maybe we can adapt the settings to make it work for your remaining core hours. For more information on core hours please read this post: What is the definition of a core hour? - make sure to take note of the last sentence in the post from Anna.
Let us know how you want to proceed. All the best!