[edit]: From the attached screenshot it now seems that the problem is in fact a missing template. The code {{My template}}
will include the content of Template:My template
. If no such page exists, the result will look like your screenshot. MediaWiki has no built in templates. You have to create them all yourself (or copy them from e.g. Wikipedia). Please read the documentation on how to use templates.
First: Are you sure that you actually have a template called Template:Infobox about
? Sorry for asking the obvious, but just to make sure...
If you do have the template where it should be, and it is appearing like raw text, completely unparsed, the most likely cause (judging from similar previous questions) is that you have a space before it in the wiki code.
This will work:
{{My template
|foo = bar
}}
This will not:
{{My template
|foo = bar
}}