Here is a simple file:
#+TAGS: math(m) music(u)
* Gödel :math:
* Bach :music:
* Gauss :math:
* Beethoven :music:
* Mozart :music:
Then I tried M-x org-tags-view
Match: +math
I expected that Gödel and Gauss will be printed, but instead I get an empty buffer that says:
Headlines with TAGS match: +math
Press ‘C-u r’ to search again with new search string
What's wrong?