There are two reasons that this message may appear:

1) The path to your Calibrations folder may not be set correctly. Start Logger Pro and select Preferences from the File menu. See where your Calibration Folder is pointed and make sure it is a valid path, you can click on the Browse button to find it (usually C:\Program Files\Vernier Software\Logger Pro (2.2)\Calibrations).

Now click the browse button next to the “Experiment Folder” option and make sure the path is set correctly usually C:\Program Files\Vernier Software\Logger Pro (2.2)\Experiments).

Now quit Logger Pro and try opening the experiment again.

2) Another explanation is that you are trying to use the ULI Force Probe with a LabPro or the Stainless Steel Temperature Probe with the ULI. Neither of these combinations run properly, the error message is true.