There's an issue in the latest update - rest assured, your data almost certainly has not been deleted. Please just wait for a fix shortly.
- What platform are you on?
- What was the error?
- On Windows, your data files are located here:
C:\Users\YOUR USERNAME\AppData\LocalLow\Visual Music Design\SeeMusic
(This folder might be hidden - you might need to Show Hidden Files in the View options in Windows Explorer)
- On MacOS, your data files are located here:
The Log file on MacOS is located at:
~/Library/Containers/com.VisualMusicDesign.SeeMusicUnity/Data/Library/Logs/Visual Music Design/SeeMusic
To easily get to this folder, use the GO menu at the top of the Finder, and select GO TO FOLDER, and copy that address into it.