Pioneer SC-LX76: Firmware Update - cannot choose "Update via USB"

I just downloaded the firmware update AVR_1_204084513160 for the SC-LX76

Following the instructions I go to "Software Update" from the "Other setup menu", but I may not select option b) which is "update via USB". This option is displayed with less contrast on the screen.

Of course I did unzip the file I got and copied the resultant 7 files into the root directory of a FAT32 formatted USB-stick. I tried actually 2 different sticks. I suspect that even does not relate to the stick or the files contained therein - for the display of option "b) update via USB" is even the same if no USB stick is connected at all.

Does anybody has an idea, under what weird circumstances (some other config) the option b) would not be selectable - or what might cause this behaviour at all ?

I have several other issues with the SC-LX76 (1. Once the WLAN connection is established - it might not work again after some time 2. The HDMI setup will hang up and display forever a "wait" status).

Thanks for your comments.

Disconnecting the power from the amp and reconnecting again let me choose the b) USB option. It then read from the stick, recognized a correct update file and after prompting "OK" began with an update - only to finish with "Update Error 6".

Nevertheless it was at least possible to choose the USB update option at all. I would want to try another UBS-Stick

Resetting is as well a good remedy for lost router access

Guess there is still some work to do for Pioneer.

In case someone is interested:

The following will solve the issues:

1. completely disconnect the power from the receiver and reconnect after some time
2. use a brandnew USB-stick - I used a 8GB Kinston DTSE9