Default Cant backup with twrp anymore !

Hey guys. Suddenly after i deleted my old backups with Root browser and wanted to make a new one with twrp, it fails
no error code or anything just a message in the top with a red text message with : Failed

My phone is :

D802 International
Cloudyflex 2.4

btw this rom is awsome ! had 48+ hours with soc 2.4 hours in one b battery !