I have installed GIMP 2.8.4 on Ubuntu 13.04 (via standard repositories). My problem is I don't see Tools window (the one I used to show/hide with the Tab key). How can I make Tools window appear?
I have this problem as well. Sometimes the tools window is inside another screen.
Ctrl + B
Try the following.
- under the Windows tab click Single Window Mode
- if the tools window isn't inside the main window, use the Windows tab again and click Dockable dialogs → Tool options.
If the tools and layer box didn't go inside your main gimp window try toggling the Single Window Mode. This helps sometimes.
In my case, the problem was caused by trying to display Brightness/Contrast window on an index color profile which Gimp does not allow. Switching to the single-window mode as illustrated in the accepted answer made the error message easier to find. The solution was slightly different in my case: Convert the image to RGB via Image, Mode, RGB and then try again to show the Brightness/Contrast dialog.