Getting a Error 404 Not Found on subcategory

I have been Googling and trying anything + plugins I can find on Google, but none of the things I tried fixed my issue.

For some reason, when I go to my URL/category --> Works URL/category/subcategory/post.html --> works URL/category/subcategory --> DOESN'T WORK (https://businessanddata.org/excel/excel-general/)

For my permalink, I am currently using the custom structure as the screenshot is showing. I have check Yoast settings and don't see anything out of ordinary. The URLs were working before the version 4.9.4.

Any help is truly appreciated!

Topic 404-error Wordpress

Category Web


The cause of this issue for future reference was the '.' in the category base, which was added to resolve a previous issue. Removing this and using /category/postname (per question) works, so will look for an alternative resolution to the category base issue.

About

Geeks Mental is a community that publishes articles and tutorials about Web, Android, Data Science, new techniques and Linux security.