How to reproduce:

Open the attached project “IN-147419”
In the menu bar, open “Repro → Generate UDS Overflow Textures”
Wait for the script to finish running and for the completion message to be printed in the Console
Close the Editor
Delete the Library folder in the project’s directory
Reopen the project
Observe the crash

Reproducible with: 6000.6.0a4 (77e2e2eea1be), 6000.6.0a7, 6000.7.0a2 (83605ec097c0)
Not reproducible with: 6000.0.79f1, 6000.3.19f1, 6000.5.3f1, 6000.6.0a3, 6000.6.0b3, 6000.7.0a1
Fixed in: 6000.6.0b1

Reproducible on: macOS 26.5.1 (M4 Max)
Not reproducible on: No other environments tested

Notes:

Editor sometimes freezes after opening
Editor sometimes crashes on step 2 instead
Version 6000.6.0a7 and newer tested in batchmode with “-executeMethod ReproTextureGenerator.GenerateFromCommandLine -reproCount 256 -reproSize 8192” command line argument instead of step 2

First few lines of the stack trace:
#0 0x000001036cab10 in alloc_block(ushared_memory_pool*, unsigned long)
#1 0x000001036d5dbc in ushared_memory_pool_alloc(ushared_memory_pool*, unsigned long)
#2 0x000001036be314 in uds_pool_alloc(uds_system_t*, unsigned long)
#3 0x000001036be144 in uds_internal_reserve(uds_system_t*, unsigned long, int)
#4 0x000001036b57d0 in uds_reserve
#5 0x000001036aa714 in UDSInterface::CommitFileEntryData(FileEntryData&)