if all workstations cannot log in QnE, check the network problem.
if only one workstation got problem, check
1. if the windows is XP service pack 2, try add a port under control panel - network connection - local area connection - advanced - setting - exception - add port :
Name : Fire bird Port numnber 3050
2. if still cannot login, try to modified the database path and save again.
3. if still cannot, try to point to server IP address in database path. example
\\192.168.0.100\C\QnE\Sampledb.fdb instead of \\Master\C\QnE\Sampledb.fdb
*192.168.0.100 is server ip address