Scheduler custom view demo throws an exception while destroying recursive event

[rockstartstudent]

I ran this project and its working perfectly fine for add/edit event but not for destroy(delete). When we destroy any recursive event it throws below exception on line db.SaveChanges(); in "Delete(MeetingViewModel meeting, ModelStateDictionary modelState)" method.

Exception - Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. Refresh ObjectStateManager entries.

[mparvanov]

The issue was not reproduced.
A possible cause for the error could be that a SQL server process is locking the Sample.mdf file under SchedulerCustomViewDemo\App_Data