First and foremost did you run down the https://599cd.com/blog/display-article.asp?ID=1193  Troubleshooter?

I'm assuming you are using a split db. Correct?  You may need to compact a repair the back end db as well.

Is it any file attachment or just this one?  
It might  be naming too.  Try to rename the file and see if it attaches.  Might something be in the name.

Just a couple of ideas to get you started.

Scott,
Yes I went over the troubleshooter.
No it is not a split db, I compact and repair often. I do backups so every time before I compact.
If the user renames the file, takes a few letters out of the name he can attach the filed. However I can from my PC attached the very same file he cant attach without any file name modification.

If I was getting the same error and reducing the file name I would say that what needs to be done. The fact that it works for myself and others and the issue is with only this user is the problem.

thanks for the suggestions Scott.

I also watched both the known error messages videos hoping to find help but no luck there.

Mark -
Is this something that just started happening? Perhaps after a change to your database?
Is it all files from the other computer or just that one particular file?

First, you already know how 'we' feel about attachments so I won't beat you up to bad...  But as soon as you can you need to work around that.  In the long run you will be grateful for the headaches it will save.  I personally NEVER use them so I don't know field size or how they are stored.

Second, while you might get away with it for awhile, I DON'T advise you have more than one person in a database with out splitting the db. Unless you can absolutely guarantee that only one person at a time is using it.

HEY RICK - CAN YOU HELP OUT HERE?  I'm out of ideas.

Where is the database stored?
Does the user have enough free disk space?

Searching around online there seems to be a few options why the error comes up, but none of them make sense when you say that the exact same file works from another PC.

It's safe to assume there's 2 databases at the least, not split. Are these databases the EXACT same? You haven't made changes on one and not updated the other yet?

The database is stored on a network drive and opened from there, only one person at a time gets into it.
The attachment field is in a subform and it just started happening to the user. He can attach a file and then go to another record attach a file and then go to another and it will not work without making some change to the file name.
These files are all PDF and saved on the network so the file names are not to long.

Its a strange on for sure, I will keep working on it.

You got me. I'd have to see it in action to troubleshoot it. You guys have covered all the bases. And yes, attachments inside your database are evil and will cause all kinds of random problems like this. That's why I preach to avoid them.