Has anyone successfully gotten a 128gb card to work?

IIRC, I had the same issue with my Sandisk Extreme 64 GB. I had to format it on my Mac using the Disk Utility (I assumed Exfat was correct). After that the Varia app was able to format the card, and it used Fat32.

I just made another thread for formatting with the varia itself since I had this issue but could not mount the card on a PC to format.  I'll copy it over here for visibility. 

To help anyone who can't format a large SD card:
I tried SanDisk Extreme microSDXC 128GB
Varia saw it as corrupt (as did my old card readers that apparently can't handle this type).

I could not mount this on my windows machine.  it also showed as a corrupt drive. 

I could not connect to my phone while the varia was in SD error mode, so the fix is:
Boot the varia with original SD card, connect to varia app, pull the SD card out, insert the new larger card.
Varia app will then tell you the card is corrupt and ask to format. Hit yes, and you should be good to go.

DATAPOINT: I was able to format and use a SanDisk Max Endurance 128GB microSD card.

I followed guidance in thread to use the Varia app on an Android smartphone which took a few attempts to pair, first via Bluetooth Smart, followed by the “Join Varia WiFi Network”.

First action once connected was updating the RCT715 firmware, which did take quite a while, and multiple attempts. Only once you have the latest firmware should you attempt to format the card, which still takes a couple or three attempts.

At no point did I have to open the card access panel and remove or replace the card - I think that may be a red herring. Just keep at it until it takes.

Which procedure do you use to reformat your memory card? I have a MAC and trying to use a 128gb card..... Any help will be appreciated!

I used the Apple Disk Utility application. I just formatted it as an ExFat volume.Then when I inserted it into the Varia it was able to erase it. It's been a while so I don't remember all the spcific steps I went throug. I think I used the Varia iPhone app to erase/format.

Put the card in your Varia and then pair and use the phone app to format it. It's the only reliable way to format the card such that the Varia can see it.

That actually didn’t work for me when I bought my card. It was the first thing I tried. The Varia didn’t recognize a card was there until I reformatted on my computer. I suppose it all depends on what format the card ships with.

It took me several insert pairing attempts before it showed up to be formatted. 
It might easily come down to what it shipped formatted as, or it might be the Varia App instability. For all the good things this product is, the App is a hot mess.