When the issue occurs, do either of the following apply?

Does the sales order number have any single or double quotes (or other weird characters) in it? 

Is the sales order number less than 7 characters?

Have you checked the users' roles to make sure they have adequate access?

I can user the "user's id" and "password" from my computer with and access the same sales order number, but I can't from the other computer.  That leads me to believe that it's not the role so much as it maybe a file a file that is missing in windows folders or c:\Sage folder?  Maybe?

Did you install the Sage workstation program on the new user's machines?  It looks like you are running from a mapped drive, but there are required program resources needed locally for anything Sage 100 to work.

Have you tried reinstalling the workstation and making sure they have appropriate NTFS permissions to the Sage 100 directories for both the server and workstation (if Advanced)?

Have you tried reinstalling the workstation and making sure they have appropriate NTFS permissions to the Sage 100 directories for both the server and workstation (if Advanced)?