This is an error I get often when I'm doing a new Drupal install, especially when I'm using the "Installatron" script on my DirectAdmin control panel:
"The directory /tmp does not exist." shows up when I click on "Administer" and then "Settings" immediately after completing the installation. This is quite possibly the most common post-install annoyance I've had to fix.
Troubleshooting this is simple...Drupal needs a "temp" folder created, called "tmp" (that's what it's called by default, but you can call it whatever you like, as long as it doesn't happen to be a folder name you're ever going to need for something else).
You can do this by opening your FTP programming, logging in to your site, browsing to the main folder containing your Drupal install (for me, this is the main site folder) and create a new folder called "tmp".
So, easy enough. Now we go back to our Drupal site, log in again (if it logged us out) and click on "Administer" and then "Settings". If you haven't sacrificed your daily goat to the Drupal Gods, your page will now say:
"The directory tmp is not writeable."
What this basically means is that Drupal doesn't have the right kind of access to the folder you just created. You made the folder for Drupal, you told Drupal what the folder's called, and now you have to tell the folder that Drupal will be accessing it.
The way I usually do this is via the online file manager provided by my hosting company (built in to DirectAdmin, used by a lot of hosting companies). I log in to my site's control panel, click on the File Manager, and browse to where my Drupal install is. Then, I find the folder I just created (called "tmp") and click to select the check box next to it, and down at the bottom of the page there's a button that says "Set Permissions To" followed by a blank. I type "777" in to the blank, press the button, and I'm done. If you don't have an online file manager, you can also use an FTP program to do this...each program has its own method for setting permissions, but you should be able to figure it out without too many problems.
A quick trip back to the Drupal Admin -> Settings page and pressing "Save Configuration" there should now return no error messages, and you should be ready to move on with the rest of your configuration / installation.
