Weird error with removing multiplayer servers from Minecraft

I entered an invalid server name, but i removed it instead of editing the server to connect to. What i thought would happen:

It would say what i named the button to join the multiplayer server would be lost

What ACTUALLY happened:

It said the name, then a weird format error.

Note: this bug DOES NOT happen with 1.12.2

How to reproduce:

Add any minecraft server to minecraft (it doesnt have to be a valid server, either)

Click delete with the invalid server selected and thats literally it