Whatsapp does not want to do a backup anymore

Hi, I have an iPhone 6 and whatsapp does not do a backup anymore. It keeps telling me that there is a problem but it doesn’t say what the problem is. So i deleted all the pictures from the various chats because i noticed it was trying to do a 1,67gb backup but it did not work. So i tried deleting the backup i had to do a knew one and that didn’t work either. Can anyone help me? I can’t uninstall the app because i have no backup anymore...

Update: solved.