Guess we need an Fabric 1.21.6 version too now :)

Hello! Hope this can solve your problem!

TL;DR

Use the latest mod version (3.7.1 for Minecraft 1.21.2-1.21.4) directly on Minecraft 1.21.6, and modifies the config file according to the following:

In config/AdvancedBackups.properties, at Line 91: setting config.advancedbackups.logging.clients to none.

#Which clients to send progress updates to. Behaviour before this was added was `ops`
#Options : ops, all, none    #Default : ops
config.advancedbackups.logging.clients=none

Specific Description

I have tried the latest mod version from Modrinth (which is 3.7.1 for Minecraft 1.21.2-1.21.4), and the mod loads just fine. When making a backup, I encountered a bug where it crashes the game since it fails to show a toast indicating the backup progress. My tests show that it is only a Render Problem.

-- Head --
Thread: Render thread
Stacktrace:
	at knot//computer.heather.advancedbackups.client.BackupToast.method_1986(BackupToast.java:41)
	at knot//net.minecraft.class_374$class_375.method_2002(class_374.java:259)
	at knot//net.minecraft.class_374.method_1996(class_374.java:94)

From that crash report, I disabled the toast feature in config, which magically solves the problem. Solution details are listed in the TL;DR section.

Even if you didn't modify the config, as long as your world is small (like a super flat world preset in my test scenario), the backup can succeed, but the game crashes very soon.

As for Minecraft 1.21.5 (#119), directly using the latest mod version without changing any config is just fine. As for the future release of Minecraft 1.21.7, try using the current mod version to see if it just works.

The mod developer seems to have been away these months, inferred from the contribution table of his/her personal profile page. Let's show our patience during his/her time away, and try our best to address the issues on our own :)

I tried this and it works, but I dont get any notification on the client side.
And with the notification turned on, the client crashes when an backup starts.
So looks to me the server side works fine, but the problem lies on the client side.

But at least the backup part works, hope this gets fixed someday :)