Cannot modify header information - headers already sent
This warning message is produced by PHP if a program attempts to send an additional HTTP header after the separator (and hence all the headers) has already been sent. In the HTTP protocol a server response consists of a group of headers followed by a body, separated by a single blank line (i.e. a line containing only a carriage-return).
Debugging a translation
You just finished a development of a new component/module/plugin, which has multilanguage support, or just finished a translation of such a Joomla addon and want to doublecheck the result, and don't know how to do it? Don't look further, Joomla supports some useful debugging mechanisms that can make it easier to locate untranslated strings and diagnose problems with language translations in installed extensions.
Debugging your own code
If your read this, then you might have playing with some code already - and as you know, nobody is perfect... all we make mistakes. But how you can find yours?
How to turn your error reporting level to maximum?
Anyone who maintained/developed something with or for Joomla, or needed to troubleshoot something on a misbehaving Joomla site knows the feeling: something does not working, and the available error messages aren't showing enough information to help you track down the root of the issue.
Any extra bit of info can help, so here is a tip for Joomla 1.7 which might help you got that.
K2 - Error decoding JSON data
After updating K2 to version 3.6.3, in the backend, when tried to edit one of items, I got this error:
Error decoding JSON data: Syntax error.
XML Parsing Error at. Error
After moving a site to a new server I found this error in the backend - at least one error per page, but casually even more.
No error number, no line number... What a heck!