(Latest updated in 04/03/2022) - (Versão em Português deste post aqui!)
Not every problem that happen to a theme is a defect that already came with it. There are many things you can do while installing or customizing a theme that can corrupt its code and cause issues.
In this post I listed the most common problems that happen with themes and showed how to solve them as well as how to avoid other problems.
Read the following table with the most common issues and if one of them sounds similar to what's happening to you, then click on all of the causes in front of it. If this post don't help you, then contact me via Ask on Tumblr and explain to me in detail what is going on with your theme (if possible, send prints to show me what you mean).
