"Unable to mount SD card"

[juntjoo2]

Unable to mount SD card https://imgur.com/a/tsx38Mj

I was able to mount another though. What gives?

I'm using a live disc, 16.0.4 on my old laptop

[coffeecat]

Did you read the error message?

unknown filesystem type 'exfat'

Exfat is not supported out of the box in Ubuntu 16.04. When it was possible to install packages in 16.04 - before it became end of life - you probably could have installed those packages needed to support exfat. That's all theoretical though. Don't use 16.04. It went end of life at the end of April last. If you use 20.04 you'll get native support for exfat without having to install anything.

I was able to mount another though. What gives?

Presumably another filesystem - probably FAT32. Yes/no?

[juntjoo2]

So how do I install it?

I tried from a suggestion elsewhere and got "could not open lock file /var/lib/dpkg//lock - open (13: permission denied)"
Then:
"unable to lock the administration directory (/var/lib/dpkg/), are you root?"

[ajgreeny]

So how do I install it?

I tried from a suggestion elsewhere and got "could not open lock file /var/lib/dpkg//lock - open (13: permission denied)"
Then:
"unable to lock the administration directory (/var/lib/dpkg/), are you root?"

You don't!
You simply need to download an .iso image of a supported version of Ubuntu (20.04 suggested by coffeecat), write that image onto a USB flash drive as you presumably did for 16.04, and without installing anything you should be able to mount and read the exFat filesystem on the SD card.
Installing anything on 16.04 is almost impossible now as the repositories have all been closed and moved to EOL URLs; it's simply not worth the hassle to continue using 16.04, nor is it safe and secure to do so.

[juntjoo2]

No I didnt. I put it on disc. So this is my first time awe that I'm "burning" to an SD card so be gentle on me

Yeahx I just don't know if it's worth trying to do any "burning" with this old laptop and external disc drive. Plus I'll be using this old Ubuntu disk

[ajgreeny]

No I didnt. I put it on disc. So this is my first time awe that I'm "burning" to an SD card so be gentle on me

Yeahx I just don't know if it's worth trying to do any "burning" with this old laptop and external disc drive. Plus I'll be using this old Ubuntu disk

No you didn't what? And what did you put on disk?
And please explain what you mean by "this is my first time awe that I'm "burning" to an SD card" as I do not understand; are you trying to burn an iso image file to the SD card?
If that is what you did in order to create a live bootable OS, you will need to check with your hardware that it can boot from an SD card; in many cases that used to be possible only if the card is put in a USB card reader rather than an SD card port on the machine.