- Download this file - https://omds-support-storage.s3.amazonaws.com/support-files/DS9500_FWUPDATE_V116_For_Windows.zip

- Plug the machine in

- Run the downloaded firmware file - if it shows as the same version, click 'start' to perform a re-installation of the firmware anyway 

- Unplug the machine - the device will update automatically, you just need to wait whilst this happens.

Also, you can try 'formatting' the internal memory on the Olympus machine as well (please note: this will erase any files stored on the device, so make sure anything important is sent or transferred across beforehand). 

- https://audiosupport.omsystem.com/en/portable-dictation/567-formatting-the-memory-card/