Drag and drop puts a copy of the file into the container fields instead of a reference. Files not stored by reference cannot be opened by double clicking the container field in Filemaker 12 nor in FileMaker 9.
If you use insert file to insert the file and select the "store a reference" option, you should be able to open the file by double clicking the container field. If it does not, you then have a bug to report. (I don't have a mac system, so I can only tell what should happen, you'll have to check and see for yourself.)
Thanks for clarifying the problem. I've tried every configuration to get the files to open, but with no success. Hopefully FM will resolve this problem soon.
If all else fails, export field contents will open a copy of the file. I realize that this is not ideal when you want to open the file, modify it and save the modified file back to its original location.
Much as I would like to upgrade to FM 12, I'm going to stick with FM 9 until the bug is sorted. I tried the "Export Field Contents' approach and it was more trouble than it was worth. Hopefully it will be sorted before September, so that I can still get the upgrade price.
Many thanks for your help.