Update to 5.12.108 failed


I am operating a MyCloud EX 2 Ultra with Firmware 5.09.115 and would like to update to 5.12.108. I have downloaded the file WDMyCloudEX2Ultra_5.12.108_prod.bin from WD-website and wanted to update manually since the automatic update failed. The download starts and goes to 100% folloed by an error message that the firmware cound not be found. What am I doing wrong?

@NoClouds Firmware 5.13.115 was released yesterday.