Game loading pauses at 51% for a prolonged period when many local worlds are present

Summary

Minecraft Bedrock for Windows experiences a severe and repeatable startup delay at exactly 51% when a large number of local worlds are present in the minecraftWorlds directory.

The delay scales substantially with the number of worlds. With my full collection of 580 worlds, the 51% pause has been observed to last well over a minute and, on some launches, several minutes. Removing the worlds from the active minecraftWorlds directory causes Minecraft to load almost immediately.

Process Monitor also shows that Minecraft repeatedly attempts to access a world_import_lock file inside every world directory, even though these files do not exist.

Environment

• Edition: Minecraft Bedrock for Windows

• Minecraft version: 1.26.4201.0

• OS: Windows 11

• PC: Microsoft Surface Pro 9

• GPU: Intel Iris Xe Graphics

• Intel graphics driver: 32.0.101.6737 (dated 4/16/2025)

• Local worlds: 580

• Worlds total approximately 10 GB

• The worlds have accumulated over many years and originated across multiple devices, including an Android tablet and previous Windows devices.

Observed behavior

Minecraft consistently reaches approximately 51% during startup and then pauses for a substantial period before continuing.

The delay increases dramatically as the number of worlds increases.

Approximate measurements:

• 10 worlds -> essentially 0 sec

• 100 worlds -> ~3 sec

• 300 worlds -> ~25 sec

• 400 worlds -> ~42 sec

• 580 worlds -> ~85 sec (warm launch; 2 minutes or more observed on other launches)

The exact time varies between launches, apparently depending at least partly on caching, but the relationship with the number of worlds is highly repeatable.

I also tested two different sets of 300 worlds, containing different worlds and a mixture of older and newer worlds. Both produced approximately the same delay (~24–28 seconds). This suggests the problem is primarily related to the number of worlds rather than one particular corrupted world.

Critical reproduction

1. Close Minecraft.

2. Have a large number of worlds in:

   C:\Users\<username>\AppData\Roaming\Minecraft Bedrock\Users\<user ID>\games\com.mojang\minecraftWorlds

3. Launch Minecraft Bedrock for Windows.

4. Minecraft reaches 51% and remains there for an extended period.

5. Rename the minecraftWorlds directory so Minecraft starts with an empty world directory.

6. Launch Minecraft again.

With the minecraftWorlds directory empty, Minecraft proceeds through the 51% stage almost immediately.

Restoring the worlds reproduces the prolonged 51% delay.

The worlds themselves do not need to be opened or loaded individually to reproduce the problem.

Process Monitor findings

I used Microsoft's Sysinternals Process Monitor while Minecraft was paused at 51%.

Filtering for:

• Process Name: Minecraft.Windows.exe

• Result: NAME NOT FOUND

revealed more than 100,000 events in approximately 30 seconds.

The vast majority of these events involved paths of the form:

...\minecraftWorlds\<world ID>\world_import_lock

For example:

C:\Users\<username>\AppData\Roaming\Minecraft Bedrock\Users\<userID>\games\com.mojang\minecraftWorlds\5MrqZN98JgA=\world_import_lock

I manually checked several world directories and found that these world_import_lock files do not actually exist.

I then counted the occurrences for individual worlds in the Process Monitor capture. Three different worlds produced approximately:

• World A: 175 occurrences

• World B: 171 occurrences

• World C: 172 occurrences

With 580 worlds, this is approximately:

580 × ~173 = ~100,340 world_import_lock checks

This corresponds very closely to the >100,000 NAME NOT FOUND events observed in Process Monitor.

The worlds selected for this comparison included both relatively old and relatively new worlds.

Other troubleshooting performed

Minecraft exhibits the same 51% delay when the PC is completely disconnected from the Internet.

Gaming Services appears healthy.

Graphics troubleshooting did not resolve the problem.

Minecraft configuration changes did not resolve it:

Expected behavior

Minecraft should be able to start without a prolonged delay regardless of the number of normal local worlds stored in the user's minecraftWorlds directory.

At minimum, startup processing of hundreds of worlds should not result in tens of thousands of repeated filesystem checks for a nonexistent world_import_lock file in every world directory.

Actual behavior

Minecraft appears to repeatedly process every world directory during the 51% startup phase, including repeated checks for a nonexistent world_import_lock file.

The amount of work increases dramatically with the number of worlds and causes startup to pause at 51% for tens of seconds or minutes.

Suspected cause

I do not know the exact cause, but the Process Monitor evidence strongly suggests that Minecraft is repeatedly scanning or processing the world collection during the 51% startup phase.

The repeated world_import_lock lookups may be one component of that processing.

The fact that approximately 171–175 checks occur for each of multiple independently selected worlds suggests this is a systematic operation rather than a problem with an individual world.

Workaround

Moving older/infrequently used worlds out of the active minecraftWorlds directory eliminates the startup delay.

Request

Please investigate whether the Bedrock Windows client is unnecessarily performing repeated per-world processing during the 51% startup phase. In particular, the repeated world_import_lock NAME NOT FOUND operations appear to be worth investigating, especially when hundreds of worlds are present.