Need a little more information.
The path you are using, its a dropbox folder... where is this folder located on everyone machine, is it under their user profile?
DoCmd.TransferDatabase acLink, "Microsoft Access", Environ("userprofile") & "\My Documents\MyApp\MyApp.mdb", acTable, "tblCred", "tblCred"
the code above is going to this... C:\Users\CURRENTUSERONMACHINE\ then \My docs etc etc... so that means, who ever is signed into the computer, it will look into the username of that person... it also helps with the differences between xp and windows 7 because their file system is a little bit different.
The code I use to make environ work in access is this.
Code:
Public Function Environ(username)
On Error GoTo Err_Environ
Environ = VBA.Environ(username)
Exit_Environ:
Exit Function
Err_Environ:
MsgBox Err.Number & " - " & Err.Description
Resume Exit_Environ
End Function
and
Code:
Public Function GetUser()
GetUser = Environ("USERNAME")
End Function
Hopfully this helps