@teastain
Hi Terry, et al

thx 1M for your effort helping me!

I've just found the work around:
As per "M5Stack Library won't install on Arduino IDE", CitrusPeel identified the issue:

The package's name "MODULE_GRBL13.2" in library.properties should be "MODULE_GRBL_13.2" (underline instead of space before 13.2).

So

download M5Stack unzip it edit file "library.properties", line to "depends=M5Family,M5Module-4Relay,MODULE_GRBL_13.2,M5_BMM150" zip it and install zipped library restart IDE update now performed flawless

@m5stack: awaiting M5Stack (0.4.6) to be released soon, as not all users having the knowledge on how to apply this "patch".

Cheers, Marcus