Before Continuing:

• Check you are using the latest version of the mods and its dependencies
• Always include a latest.log if you are crashing
• Remove known hacky mods such as: Optifine, Fabric API/Connector on forge, and every kind of hybrid server like Mohist and Velocity. None of these are supported. Also try without other lesser usual suspects like Sodium and Lithium.
• If you are unsure which mod is the culprit.
  Disable all of your mods and enable them 1-2 mods each time to isolate the culprit
• Confirm that there is no existing issue with a similar description submitted in the list of issues.

Version

1.21.1-FABRIC

Supplementaries Version

supplementaries-1.21-3.2.0-beta-fabric

Moonlight Lib Version

moonlight-1.21-2.19.1-fabric

Describe Issue

This was copied from the "Bugs and Issues" Discord Thread.

Hi there!

Odd little problem I noticed in the latest Supplementaries-Version: When I put an item (rope or chains for example) into the pulley block, then close and re-open the interface, the item is invisible. It's still there, I can remove it by clicking on the "empty" pulley block slot. The item just happens to stay invisible until then.
The pulley block otherwise works as intended, it's really just this issue with the interface.

If you have the time, could you maybe look into this? Thank you!

Additional Information:
This issue occurs on a minimal instance, but no error is shown in the logs.
But, when only installing Supplementaries, Moonlight and ImmediatelyFast, when accessing the pulley block after leaving an item inside, an error turns up in the log: "A mod tried to use the ImmediatelyFast batching API, but it is no longer available in 1.21."

Here is an example of the error:
https://mclo.gs/jLimDnw (begins at line 224)

try new version

Tried newest version - issue still happens, though the ImmediatelyFast-Error is gone.

I noticed that the item that "vanishes" reappears in the pulley block slot when...
a) ...you try to place a different rope or chain item in the slot via shift-clicking on the new item.
b) ...you click a random spot outside of the inventory while the pulley block slot item is not visible.

I hope that helps!

hmmi still cant replicate . maybe its something with fabic because on neoforge it shows as soon as i open

Hmm, I'm assuming you do, but are you using Fabric 0.16.14? That's the version I'm using, in addition to Fabric API 0.116.3+1.21.1.