in mendix pro when I open app at first time then repoen app then Error Occures in database connection

I have an error , when run mendix application at first time the app work successfully but if close the app then run it again without any changes , the app crashes with these errors of database connection , can anyone help me to solve this problem , all photos for this error and data model are below (Hint) I tried many versions of mendix pro and the same error occure
2 answers

 if the DateTime in your Desktop in arabic, you have to change it to english because mendix read this date , and when it be in arabic mendix can not understand it.


Hi eslam elassal, 

Please check in which format you store the $TrainingEvent/StartDate or the $TrainingEvent/EndDate or $Registration/Date…
Seeing the error message:  data exception: invalid datetime format,

I'm guessing something is going wrong in one of the above fields.