If you delete an open check file by folder, an error occurs when saving the check file.
If you delete a folder that contains the checklist while the checklist is open, as shown below, an error occurs when you close the open checklist.
When you close the dialog here, you will see a dialog similar to the one below. If you want to completely delete the checklist you are editing, select No. If you really want to leave it, select "Yes" and follow the steps below.
First, create a folder with the same name as the folder you just deleted.
The checklist you are editing will then be closed and saved. After that, select "Update" from the checklist menu to display the previous checklist.
This bug will be fixed in a later version.