I found the error:
I created a new application with the application number it had before and exported the new application.
(I read this articel before: Recover a deleted APEX page or application | APEXPLAINED)
By viewing the application-file I saw all the LOV´s of the application are still inside the file. So I looked for the Shared Components / List of values and found all LOVs of the application.
So I deleted them all and imported my application again and now the import worked fine.
Is it a bug that the LOV´s of the application are not deleted together with the application?