inserted disk not readable by this computer mac

[waydi]

Hey there! I am writing to you with a huge request. Well, for some time I am using a rather fast Micro SD card 128GB with Nifty adapter to expand the internal storage of my MB Pro '13 early 2015. Unfortunately a few days ago I had to remove the card to connect another. When reconnecting I received the message: Inserted disk is not readable for this computer.
Disk Utility show that the computer correctly detects the card's capacity, but does not show any active volume and the drive status as "Uninitialized".
"First aid" unfortunately has no effect in this case.
I tried several applications to recover files, but none find anything. Do you have any ideas how to solve this problem? I want to bring the card back to life and recover the currently unavailable files.
Thank you in advance and best regards!

 

[Fishrrman]

A VERY IMPORTANT question:
When you removed the card a few days ago, did you drag it's icon to the trash first to dismount it, or.... did you just pull the card out?

The VERY FIRST THING I would try:
Get a USB card reader and try the card in that.

 

[ZapNZs]

A VERY IMPORTANT question:
When you removed the card a few days ago, did you drag it's icon to the trash first to dismount it, or.... did you just pull the card out?

+1 for the importance of this question.

Further, was the filesystem you formatted this in by chance ExFAT or FAT32? (Or did you begin using it out of the box without formatting it?)