EDIT:
Figured it out.. It's a Samsung tablet I had plugged into the computer charging..

It's powered off but shows up as USB Serial Device (COM5) in device manager.. If I unplug the tablet, or uninstall COM5 the error goes away.. Seems bfgminer sees COM5 & tries to mine with my tablet

I'll leave this post up in case anyone else runs into this issue. I bet other devices could result in errors as well.. I figure there's a way to disable COM5 on command line so I'll look into that or just keep it unplugged.
ORIGINAL POST:
Anyone know what this means?
FutureBit Write error: Invalid argument
Odd thing is it mines fine other than complaining at startup and repeatedly while mining:
[2018-12-23 18:03:41] FutureBit Write error: Invalid argument
[2018-12-23 18:03:42] Accepted 0795fdcc MLD 0 Diff 514u/244u
[2018-12-23 18:03:42] Accepted 0231393a MLD 0 Diff 1m/244u
[2018-12-23 18:03:43] Accepted 0c411dbd MLD 0 Diff 318u/244u
[2018-12-23 18:03:44] FutureBit Write error: Invalid argument
[2018-12-23 18:03:44] Accepted 03873fc3 MLD 0 Diff 1m/244u
[2018-12-23 18:03:44] Accepted 0b6289fd MLD 0 Diff 343u/244u
I've got 4 Moonlander 2's all doing the same thing, 1 alone or all together. They work fine using same hub on rasp pi & another win10 box but 2nd win10 box giving this invalid argument error. Of course the one I want to mine with is the one giving the error.. lol
Nothing exciting in my config:
bfgminer.exe --scrypt -o stratum+tcp://pool:5555 -u user -p x -S ALL
It gives the same error if moonlander 2 plugged in directly to computer (usb2 or usb3) or in hub and in fact it gives the same error
even if no moonlanders are plugged in at all.. I installed the win10 drivers listed on the 1st post:
https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers About only thing I haven't tried yet is rebooting because I'm unable to conveniently at the moment but will do that once I'm able.
Thx
Bill