How to fix crashes on startup

The most likely reason RawTherapee might crash immediately after starting is because it loads a problematic processing profile (PP3, they store all the tweaks you make in RawTherapee, one PP3 per photo) or a problematic photo. The reason one of those could be problematic might be because it is corrupt, but it could also be that the file in itself is fine but triggers a bug in RawTherapee, or some aspect of it is unsupported, such as character encoding of the metadata, multiple layers in an image, more or less than three color channels, etc.

Note: RawTherapee only supports images with three color channels - RGB (or possibly CMY). If you try opening a directory which contains grayscale image files, or ones with four color channels (e.g. CMYK) RawTherapee will throw up an error popup window. Move these out from the startup directory elsewhere, as described below. Of course it might be a valid RGB photo or processing profile that crashes RawTherapee, but first check for non-RGB ones, as these are quite common causes of crashes.

To find the cause of the problem, we will begin with the least invasive and most informative steps, and escalate up to the most destructive steps if the informative ones do not help.

1. First, have RawTherapee use a different startup folder:
   1. Find the "options" file as described in the File paths page.
   2. Open the "options" file in a text editor like Notepad++ and see what these two lines are:

      StartupDirectory=last

      StartupPath=C:\\Documents and Settings\\Administrator

   3. Make sure the first one is

      StartupDirectory=last

   4. Create a new empty directory somewhere on your disk,

      Windows: C:\\foo

      Linux: /home/bob/foo

   5. Change the StartupPath= argument to the directory you just created (it must be an existing directory which does not contain any photos or PP3 files, and you have to type the whole, absolute path, no shortcuts, with double back-slashes if you use Windows) e.g.

      Windows: StartupPath=C:\\foo

      Linux: StartupPath=/home/bob/foo

   6. Now try starting RawTherapee again. If it works, then you know that one of the photos or PP3 files in the original StartupPath is faulty, so skip step 2 and jump straight to step 3. However, if RawTherapee still crashes right after starting, proceed to the next step.
2. Delete the batch folder:
   1. Find the "batch" folder as described in the File paths page, and delete it.
   2. Now try starting RawTherapee again. If it works, then you know that one of the processing profiles of the photos you sent to the Queue is faulty. Finding which one would be a pain in the ass and I wouldn't bother, but if you really want to, then the next main point section "Nail it down" applies. If it doesn't work, then the problem is not a faulty photo or PP3, the problem lies elsewhere, outside the scope of this guide.
3. Delete the cache folder:
   1. Find the "cache" folder as described in the File paths page.
   2. Move (cut) the cache directory elsewhere, somewhere where RawTherapee will not look. Instead of moving it you can just delete this cache directory, but be warned: if you set RawTherapee to only store processing profiles (PP3) in the cache, then you will lose your tweaks. You will not lose any photos. If you do not know whether you did, then you did not, because by default RT stores processing profiles alongside the raw files, not in the cache.
   3. Now try starting RawTherapee again. If it works, then you know that one of the processing profiles files in the cache is faulty. Finding which one would be a pain in the ass and I wouldn't bother, but if you really want to, then the next main point section "Nail it down" applies. If it doesn't work, then the problem is not a faulty photo or PP3, the problem lies elsewhere, outside the scope of this guide.
4. Nail it down

   You've established that either a processing profile or photo is to blame for the crash. It would be most helpful if you could nail the problem down to a specific file, so that we can analyze it and develop techniques for dealing with such an enemy. See the guide to stack-backtraces. If you can follow those instructions, a backtrace would be of great value, yet even a backtrace might not expose the problematic file, so read on. By now you should know which directory contains the faulty file(s) and you should have either set RawTherapee to start up using a different directory, or you have moved the cache out somewhere else. To make it clear, let us assume three things:

   • That the directory which contains a file that crashes RawTherapee is C:\photos\bugs and that your options file had StartupPath=C:\\photos\\bugs
   • That you changed StartupPath=C:\\photos\\bugs in the "options" file to the existing and empty StartupPath=C:\\foo
   • That there are 100 photos in the faulty directory, 001.raw - 100.raw

   Let's find the faulty file:

   1. This is grunt work. I use raw files as examples, but in your case it might be the processing profiles, not the raw files. Or it might be JPEG files, PNG files, or any other file in the faulty dir. What we're going to do is to keep halving the pool of possibilities until we find the problem. This is the fastest way.
   2. If RawTherapee is running, close it.
   3. Move half of the files (001.raw - 050.raw) from this problematic directory (C:\photos\bugs) back into a directory that RawTherapee reads (C:\foo)
   4. Start RawTherapee.
   5. If it crashed, go to the next step. If it did not crash, then go back to step 4.3, but move the other half (051.raw - 100.raw).
   6. Move half of the files you just moved (001.raw - 025.raw or 051.raw - 075.raw) out from C:\foo and back into the directory which RawTherapee doesn't read (C:\photos\bugs).
   7. Jump back to step 4.4. Repeat until you find the faulty file.

Zip this faulty file (even if it's a text PP3 file, because zipping it will prevent any website from touching it and possibly removing the cause of the crash [it could be something you can't see]), upload it to FileBin and link us to it in the Forum.