Below are instructions on how to update the firmware on your Reverb. Attached are the firmware files and the changelog.
How to upgrade your Reverb's firmware
1) download the firmware file from below. It should have the format eervXXXX.bin where the XXXX is replaced by the version number.
2) copy the file to the root directory of a high-capacity SD card that's been formatted FAT32.
3) insert the SD card then power on the pedal.
4) the preset LEDs should flash yellow for a bit, then all turn green when the update is complete. This should take about 15 seconds. Wait till your pedal boots normally and is playable.
5) remove SD card, turn your pedal off and then on again and you're good! (this part is a little redundant, but it's good to cycle your power just to make sure everything is nice and working!)