The following error message usually indicates that something is wrong with the exported configuration files on the USB or the USB itself.
Please make sure that the configuration has been properly exported from the Evoko Control Panel. If properly exported your USB should have a folder named "Evoko Room Manager" in the root directory which should contain around ≈20 files.
In case the "Evoko Room Manager" folder only contains a single "MeetingRoomConf.xml" file that means that something when wrong during export.
If the issue continues to occur then please try a different USB (4GB or less, FAT-formatted is recommended).