"unable to create type string"

When I use the Command+shift+4 command to capture a screen selection I am told that Your screen shot can't be saved - "unable to create type string" - this happens only with the MacBook Pro we updated to Snow Leopard - our MacPro is fine. Any thoughts as to where I should look?

Hmm...Which version of OS X did you upgrade from? Was it a straight upgrade (i.e. you didn't erase the disk first)?

Along with the above comments, run the latest Combo updater again and see if that makes a difference.

I'm gonna go out on a limb here...

Let's suppose that at some time you came across the following (correct) tip:

Quote:

There's a hidden setting to determine what file format Screen Capture uses for the files it creates. The default is PNG, but you can change it by entering the following Terminal command:

defaults write com.apple.screencapture type string

Just replace string with the desired format, one of pdf, png, jpg, or tiff.

Let's further suppose that you typed that in, but forgot to replace the word "string". I imagine you'd get exactly that error message, since "string" is not one of ScreenCapture's supported file formats.

You can see if something like this has happened by entering:

defaults read com.apple.screencapture type

and/or revert to the default file format with:

defaults delete com.apple.screencapture type

Just a thought. I'm gonna come in off that limb now.

If that doesn't work, before rushing out to re-apply combo updaters and and other such big guns, try the basic trouble-shooting steps. Test with a different user. Try temporarily deleting the relevant preference file (~/Library/Preferences/com.apple.screencapture) and restarting. Heck, just try restarting (because it's amazing how often that fixes what ails you).

the plist that stores the screen capture type is almost certainly corrupted, since "string" is a tag name in the file and does not belong in a data field.

Plists tend to get imported via A&I and your problem may follow you around like a well-trained dog.

To elaborate on V1's excellent response, the responsible property list (plist) file is in your home directory ~/Library/Preferences/com.apple.screencapture.plist

Simply drag that file to the trash and it will be recreated the next time you use Screen Capture, but with the default file format. The ubiquitous freeware OS X configuration app TinkerTool is among the many utilities that can change the screen capture format to whatever format you desire.

Go to terminal and type:

defaults write com.apple.screencapture type png