Joomla! Documentation™

I see that in Joomla 1.5 the function where you could see if the nessesary directories where writable, is removed. I always get into trouble when trying to install components/modules/plugins because of permission problems. In addition the errors from Joomla seem pretty random depending on where there is a permission problem. Could someone here please say which directories commonly need to be writable for a successful installation? this would certainly be very helpful...

Jonas:))