Hello,

I have created a test application with the calendar. When running it everything works well.
After changing the application type from 'Windows Form Application' to 'Class Library' it goes wrong.
When calling the calendar from our ERP software the first time it goes well. When closing the calendar and starting it the second time the following error occures:
An entry with the same key already exists.

I noticed when I don't create appointments everything goes well. So I think the problem is the appointments are saved when closing the calendar. When starting it again the appointments are created again.

I use the clear command at the beginning to clear everything. This doesn't help.

Can you give me a clue to close everything in the good way so I don't get the error the second time?

Thanks in advance.

Hello Meppy,

May be it's difficult or maybe there no time.
Only to be sure, did you get me email with the detail information of the error?