flash Xposed | "cp: write error: No space left on device"

Hello, I have a Problem while flashing Xposed.
I have the current TWRP and Firmware Version

Yesterday I had install the custom Rom ViperOne on my device.
Then i want to flash Xposed. But every time TWRP shows : "cp: write error: No space left on device",
but my storage have more than 10GB free space.
Please help