Where is the file located when you insert it? Is it possible that the file is located in a folder to which not all users have at least "read access permission"? This would need to be a shared drive, have all users mounted/mapped to that folder identically to you?
All users have the same "permissions" on the folder (which is located on a shared drive).
What does "mounted/mapped" mean, my English is not that strong?
I don't know for sure that this is the case, but what you describe is consistent with the other user inserting the file from a location to which all users have identical access and you inserting from a location to which all users do not have access. That can be a file path issue or a OS level permissions issue.
In windows, If I insert a file by reference from a particular shared folder, all other users must have "mapped" the same drive letter to the same exact folder or the file path created when you insert the file will not be a valid file path to the file for the other user. These drive letter mappings can be lost from a computer from time to time and need to be reestablished.
"mounting" a shared folder on a Mac system is a similar situation.
Plus the file path to the file that is valid for a windows user will be invalid for a mac user and vice versa.
These issues are the reason why External Storage is now an option for container fields in FileMaker 12 and 13.
when you say In windows, If I insert a file by reference from a particular shared folder, all other users must have "mapped" the same drive letter to the same exact folder or the file path created when you insert the file will not be a valid file path to the file for the other user. These drive letter mappings can be lost from a computer from time to time and need to be reestablished.
i wonder: if this is the case how does it come that i can open the files that another user inserts, who could not open the files that i inserted?
Think i have to talk to our IT-team one of these days...
To repeat, my original suggestion was that the file the other user inserted was not located in the same exact directory as the file you inserted.
Another possibility that I have alluded to here is that Mapping or mounting a drive can change so this can work one time and then fail the next. I have a system here where we use digital cameras with "EyeFi" SD cards to take pictures of customers (a legal requirement) and then users select from a list of recent images to link that image record to a given transaction record in our system. I've had to add buttons that create and perform command lines in a batch file to "re-map" the folders used so that users can click a button any time that images suddenly aren't appearing in container fields.
You may find the exploration file found here: Exploring the use of a $Path Variable in Scripts to be useful. You can insert a file by reference into a container field in this file and see the exact file path inserted into the field as well as all other text inserted at the same time. So the next time that this happens, you can insert into the container field in this file and see the exact file path involved.
You were spot on: different users create a different path to the same file. I sended this oinformation to our IT-manager. Guess he will come up with a solution.
Here's an option to consider if you can't transition to external storage (a feature of FileMaker 12, 13):
Set up a global container field for adding files. Have your users insert a file into this field. Use the OnObjectModify trigger set up on this field to run a script that:
a) exports the file to the designated shared directory
b) inserts the file into the correct container field of the correct record, but from the location to which it was exported.
This way, users can insert a file from anywhere, even locations specific to their computer, but FileMaker puts it in the correct storage location for you/them.
Then it's just a matter of setting up the computers to consistently map/mount the shared directory on each machine...