I have been flying fairly regularly and when I went to fly today, no connections.

• Aircraft has all solid red lights indicating, Critical Error
• Transmitter will not connect to aircraft
• Device will not connect to Transmitter; multiple android devices tried.  Receive a notice that the "connected device is unable to access data on this device"
  

Battery swaps, cable swaps, uninstall/reinstall app...  no change.
Due to the lack of any connections I was unable to attempt firmware updates via app.  I tried through DJI Assistant 2.  Multiple attemepts failed, on multiple firmware versions, giving error codes 0x020104 or 0x020106.

I am at a loss.  Any advice or assitance would be welcome!

Try using an IOS device!

I think you need to contact support for this one as you have tried all the normal fixes.

May I know  the current version of your drone if you still remember it? If it is prior v1.4.000, you can provide me with your DJI account, I will forward you a beta to try first.