InDesign shuts down when dealing with Arabic

Question

The program shuts down after approximatelly 30 seconds as soon as I start playing with the font - changing to Simplified Arabic etc.
The same problem occurs on two seperate computers, where CS was installed  - work computer where I'm using a purchased version and home computer where I have a trial version installed.
I didn't seem to have this problem until I downloaded a script for RTL.
Now I have donwloaded the Arabic version of CS6 with an in-build RTL option and the problem is still present.
English materials work fine.

Answer 1

Um. This post is full of guesses.
I am going to guess that under Edit -> Preferences -> Clipboard Handling you have "All Information" instead of "Text Only." Is my guess correct?  Because copy/pasting RTL stuff from Excel has been problematic for me in the past when Excel's native styling made it into InDesign.
I would furthermore guess that:
1) it worked before because the RTL text flow was turned on in Word, and that info carried across on the clipboard, but
2) now when you try to turn on RTL text flow in InDesign it's freaking out on "Left to Right" versus "Default direction" properties
So my final guess would be that a change in workflow will end the crashes. It's a long shot, but I would suggest that you either
1) Only File -> Place documents, never copy/paste
or
2) Change the Clipboard Handling settings to Text Only, and continute using your copy/paste workflow. But the text will always flow in the wrong direction until you apply one of the RTL paragraph direction scripts.
I'd strongly sugggest that you abandon the habit of copy/pasting complex-script text. It's a disaster, really. Most of my complex-script workflows tend towards trying to strip as much Word garbage off of text as I possibly can, all the way down to raw Unicode text when I can do so, and then placing those stripped-down files into Word.
When I can't do that (when I need to preserve some parts of Word formatting), one trick that I've used in the past is to have character styles called "Overt LTR" and "Overt RTL" in Word when I needed English words in the middle of Arabic paragraphs, and vice versa. This is necessary because InDesign has a setting that I don't think Word has: "Default Direction." So in a mixed paragraph, it will try to apply LTR to Latin script and RTL to Arabic script. This causes problems of all kinds, especially when you have mixed numerals (e.g. phone numbers in Arabic numerals, but all other numbers in Hindi numerals).
But since Word and InDesign handle complex and RTL scripts quite differently, there will always be some pre-InDesign hygiene necessary, and some significant cleanup within InDesign once the text is in.