MediaLab works most reliably when the computer is running the .exp and .que files on the same hard drive on which MediaLab is installed. Many people can and have successfully used MediaLab like you are with a server. However, moving the files onto a server away from the hard drive where MediaLab is installed introduces new possible layers that could interfere with running the program. Here are a few things you might want to check.
1) Do all of the user accounts running MediaLab have full read/write access-preferably Administrator- to the place with the data folder?
2) Did the internet or connection to the server possibly go down while running MediaLab?
Jason Reed
Empirisoft Software Support Specialist