So you wanted to import the theme demo data, but after about 30 seconds you get the 500 (internal server) error?
What to do now?
First check, if anything at all was imported. Click through the Post, Pages, Media and other Custom Post Types in the wp-admin dashboard.
If something has imported, then just go back to Appearance -> Import demo data and import the same demo data again.
You can repeat the same import a few times (give it 7 tries max), but refresh the page between each try. The demo import should finish with a success message on one of those 7 tries.
Once it does, you are done with importing.
This method should resolve issues for 80% of our theme users, so please try this first.
Why is this 500 error even happening?
The server, where you are hosting your WordPress site has some sort of issue, when importing the content and break the import. There are many reasons, why the server can’t process the import…
If the above method does not work to resolve this issue, then you can also check the One Click Demo Import documentation of common import issues and how to resolve them.