MAS has stopped working when opening Sage 100 on Windows 2008 64-bit Citrix/Terminal Server


Error: “MAS has stopped working” when opening Sage 100 ERP on Windows 2008 64-bit Citrix/Terminal Server


Disable PEP (Product Enhancement Program)

  1. Login to Sage 100 ERP as the Administrator, which will bring up the Administrative Tools task.
  2. Click, Sage Product Enhancement Program
  3. Uncheck, Participate in Program
  4. Click, OK
  5. Click, Close


  1. Open Library Master, Utilities, Data File Display & Maintenance.
  2. Type, “SY_SYSTEM” for the file name
  3. Click, Edit and select the field, EnablePEPForSystem$
  4. Change the value from ‘Y’ to ‘N’.
  5. Close, window


If necessary, seek the assistance of Acute Data Systems to help provide assistance with this process.