General Info

• I didn't added any mods
• I get this issue consistently in single-player
• I get this issue consistently in multi-player
• I am crashing and can provide my crash report(s)
• I am using the latest version of the modpack

Your launcher

HMCL

Modpack version

4.2.8

Describe your issue

Hello,

Please note that English is not my native language, so I'm using AI and translation tools to help communicate this issue clearly.

I've encountered a significant performance issue related to large-scale block breaking operations in survival mode. The problem occurs consistently under the following conditions:

1. Using FTB Ultimine with chain mining set to 128+ blocks
2. Using JustHammers mod's Netherite Destructor Hammer with 5x5x5 area mining capability
3. Using Thermal Series' Earth Grenade for area destruction

In all these cases, when performing large-scale block breaking operations manually in survival mode, there is a very noticeable block breaking delay. The blocks disappear slowly from the center of the mining area outward, creating a "wave" effect rather than instant destruction.

After extensive testing using a binary search method to systematically disable mods in batches, I have conclusively identified the Rats mod as the source of this performance issue. When the Rats mod is removed from the modpack, all of the described block breaking delays completely disappear and operations return to normal speed.

The issue appears to be specific to:

• Survival mode only (creative mode works fine)
• Player-initiated operations (automated/FakePlayer operations work fine)
• Large-scale block breaking operations

This suggests that Rats mod is adding some event listeners or processing that significantly slows down block break events in survival mode when players perform area mining operations.

Thank you for your attention to this matter.

Steps to reproduce the issue

No response

Additional Information

No crash occurred

Fixed in update v4.3.1