Things you should know when using themes and plugins with wordpress:
1. Some themes might break plugins.
2. Some plugins might break themes.
3. New versions of wordpress might break some plugins and themes.
Some tips to avoid these problems:
– Always keep your wordpress version up to date (it will keep your blog more secured)
– Always keep plugins and themes updated to latest version
– If something breaks then do this:
a. Activate another theme, if problem persist then, go back to your original theme and start deactivating each plugin one by one until you find the culprit. If you do find one or more plugins causing problems then I suggest you contact the plugin’s owner for a solution.
If they do not provide a solution that means their plugin is no longer usable and you should get another one that does the same thing.
b.The same with theme, if your theme is breaking things in wordpress or with plugins then contact owner as well for a solution.
Another tip: Before you update a wordpress blog to latest version, make sure all plugins are upgraded to latest version and theme as well. You should always make a backup of your database before upgrading to a new wordpress version.
There are a lot of free plugins and themes but not always is the right choice when it comes to support. I would suggest sticking with paid plugins and themes since they are more likely to stay updated with the new wordpress versions.