Fixed crash
Fixed crash

bq/Ultimaker-Cura,ynotstartups/Wanhao,ad1217/Cura,ynotstartups/Wanhao,markwal/Cura,Curahelper/Cura,totalretribution/Cura,fxtentacle/Cura,Curahelper/Cura,totalretribution/Cura,fieldOfView/Cura,markwal/Cura,hmflash/Cura,hmflash/Cura,ad1217/Cura,fxtentacle/Cura,fieldOfView/Cura,senttech/Cura,senttech/Cura,bq/Ultimaker-Cura