Attempting to read illegal array index AX 2009

If you have the error like this when printing to pdf or run a function in AX that create the pdf file. It could be that the document you are trying to create has a special character that your pdf driver doesn't accept it.

Look up at every text field in the document, remove the special character, then try again, it should work.

It can be in the order line name, item name, comment, etc..

User Cache issue when update logic in AX 2009

You may into a situation when you need to update a change in a form in AX 2009 in production environment, and for some reasons, one or more users do not see the changes even after you restart AOS service, clear their user cache.
The solution is to make the user admin in AX, go to the object that needs to be updated, compile and restore to get the latest changes. Test to make sure the change is now applied to them. Revoke the Admin permission, done.