You may receive an error for various reasons. The most likely is that your Sweat Patch did not capture enough sweat during your workout to register a result. If that is the case, plan your sweat test for a longer, higher intensity workout.
Another reason may be that the lighting conditions are poor when you scan the Sweat Patch. Move to an area with bright light (preferably natural light) when scanning the Sweat Patch with the Gx app. Try to ensure that there are no shadows over the patch when you scan it
Lastly, the Sweat Patch and our algorithms were developed for running, cycling, basketball, football, soccer, lacrosse, tennis, and HIIT workouts with a duration between 30-90 minutes in weather conditions from 60°F to 100°F. Conditions outside of this may not produce a valid sweat result, or may produce a result with a larger margin of error.