Many users write their content directly into the dashboard, while others often copy the content from Microsoft Word, Google Docs, etc.
When copying and pasting content that has been formatted using other tools, such as Word, Google Docs, etc, you end up introducing formatting issues. For example, you may see rogue code, extra spacing between characters, or, the page won’t render anything. As the amount of junk builds up in posts, pages, and files, it can even slow down your site, as the search engines are having to read through more code.
Solution
To minimize this issue, whenever you copy and paste content into WordPress, you should switch to the Text editor by clicking on the dedicated Text tab in your post or page. This will “clean the text” from any previous formatting.
You can then switch to the Visual tab and use the tools in the toolbar to format your content, such as bold facing words, or creating hyperlinks.
An extra step, but well worth it to avoid problems.