[RESOLVED] Error when creating form

[Karl.Green]

As soon as I click debug, I get the following error:

InvalidOperationException was Unhandled
An error occurred creating the form. See Exception.InnerException for details. The error is: Value of '01/01/0001' is not valid for 'SelectionStart'. 'SelectionStart' must be greater than or equal to MinDate.
Parameter name: SelectionStart

On my form I have a MonthCalendar control which is what I assume the error is about as I don't have anything else with a SelectionStart property.
The MinDate for the month calendar is 01/07/2013
The MaxDate for the month calendar is 31/12/2199

The Selection range is 17/07/2013, 17/07/2013
The MaxSelectionCount is 1.

This happens before the form load event which I have a breakpoint on, so I am not sure where to look to start fixing it.
It brings it up in a new tab called "No Source Available"

[dunfiddlin]

Is DD/MM/YYYY the correct date format for the language you're using on the machine? It should be automatically adjusted but the only explanation for this behaviour I can think of is that it's trying to interpret 17 as a month rather than a day.

[Karl.Green]

Sorry, I worked it out before anybody commented but I couldn't work out how to delete the thread.

The date format was correct.
The problem was that one of my radio buttons is checked on the form by default, last night I added code so that when you check the radio button, it sets the month calendar's SelectionStart to a variable called CurrentDate.

However what I didn't realise until now was that other procedures (such as the radio button checked change) can be executed before the form load event.
My CurrentDate variable hadn't yet been initialised as it is initialised in the form load procedure so it's value was '01/01/0001', this is what caused the error.

For anybody else who finds this thread, I clicked something like "copy exception info" in the error message and went through the lines of code it said in there one by one until I found the offending line.

[dunfiddlin]

Sorry, I worked it out before anybody commented but I couldn't work out how to delete the thread.

No problem. Marking the thread resolved is the right thing to do but it helps if you just add a note to say how you did it. Not only does it mean we know you didn't just mark it accidentally but it may also be of help to someone else who encounters the problem later.