Anyone have issues with the new Feather M4 Express?

I have bought two and so far have not been able to program from the ardiuno IDE. Is any one having issues or do you have it working ok. My issue is as bellow which is copy from Adafruit forum (which has no replies).

Can someone from adafruit support please help, it would be much appreciated. Thanks

Update 6Sept18
So I purchases a second M4 feather express and get exactly the same.

When I plug in I get the green pulsing neopixel and nothing on Pin13 led and I can see the flash drive in windows 7 ok.
I dont yet see a serial port for the feather (this is the same for all the Adafruit M0/M4 boards I have but the other program ok).
If I double click the reset button the neopixel goes steady green, pin 13 pulses read and I see the Featherboot flash drive. OK.
If I try to load blink from IDE it cannot find the board. If I double click while the IDE is enumerating through the ports then the IDE finds the board but fails to load with the error message posted below.
On the same setup, Trinket M0, Feather Express M0, Itesybitsy M0, Itsybitsy M4 all load after the double click of reset.

Probably not related, but the charge indicator LED (ok its orange not yellow) flashes at a high rate all the time on both of these M4 Feather express boards.
Looking at the circuit diag and the data sheet , with no battery connected the STATUS pin on the MCP7831 should be in a high Z state ie LED off.
This is the same on several computers with a number of different USB leads.

previous post
Hi just got a new M4 express and having issues loading.

Win7 - Latest Adafruit drivers installed
IDE 1.8.5
All Libs updated.

I can upload ok to Trinket M0, Itsy M0, Itsy M4, Feather M0 Proto,
The M4 express goes into bootloader mode ok with a double click but the IDE fails to upload with error below.
I also notice on this board the yellow led (lippo ?) is always flashing (very fast). I am only powering vi USB.
Any help appreciated.
Thanks

Found upload port: COM48
C:\Users\robert\AppData\Local\Arduino15\packages\arduino\tools\bossac\1.8.0-48-gb176eee/bossac -i -d --port=COM48 -U -i --offset=0x4000 -e -w -v C:\Users\robert\AppData\Local\Temp\arduino_build_389080/Blink.ino.bin -R

Set binary mode
Device unsupported
version()=SU
Connected at 921600 baud
readWord(addr=0)=0x55534253
readWord(addr=0xe000ed00)=0x30303030
readWord(addr=0x400e0740)=0x23342c30
readWord(addr=0x400e0744)=0x53425300
An error occurred while uploading the sketch

Have you set up the Arduino IDE as described here? https://learn.adafruit.com/adafruit-feather-m4-express-atsamd51/setup