When using Windows Defender as your antivirus, if you are receiving an error upon closing MSP “Could not save database at C:/Users/Public/Documents/Ministry Scheduler Pro/. It is possible you do not have access to this folder” as well as a pop-up from Defender stating "Unauthorized changes blocked," this may be due to a new feature in Defender for Windows 10 called Controlled Folder Access:
Microsoft has made instructions available on how to turn this feature on/off which can be seen at https://support.microsoft.com/en-us/help/4046851/windows-10-controlled-folder-access-windows-defender-security-center.
If you do not wish to turn this feature off entirely, you can follow those same steps above to find the Controlled Folder Access settings. Here you will see the option to Allow an app through Controlled folder access. Select this option and locate your Ministry Scheduler Pro executable under C:\Program Files (x86)\Ministry Scheduler Pro 7:
Once you have added this exception to Controlled folder access MSP should run without any further errors from Defender.