This error message can appear if D-Lab has not been closed properly. Please do the following:
1. Open the task-manager and end the process "mongod"
2. Go to C:\data\db (default) and cut (NOT delete) all folders and the 5 files called:
......and save them on your desktop.
3. Open D-Lab
4. You can delete the cut files if D-Lab starts properly now.
These steps will delete some settings, the layout and the configuration of a incomming Data Stream, but none of the recorded data.
Please make sure that you don't delete any other files in the C:\data\db that has the names of your D-Lab studies. Otherwise we cannot restore this data.
In case this does not solve the issue, please contact the Ergoneers Support (firstname.lastname@example.org).