this is a band-aid fix for random crashes when switching between presets with multiple segments - crossfade disabled.
!! adding type initializers fixed it for me on -S3, however I still see (less frequent) crashes on esp32, due to heap corruption.
It took me hours to get a meaningful stackdump:
assert failed: heap_caps_free heap_caps.c:360 (heap != NULL && "free() target pointer is outside heap areas")
Backtrace: 0x40084ee1:0x3ffb2570 0x4008e341:0x3ffb2590 0x40094709:0x3ffb25b0 0x4008534a:0x3ffb26e0 0x40094739:0x3ffb2700 0x400e9037:0x3ffb2720 0x400e917c:0x3ffb2740 0x400eaeeb:0x3ffb2760 0x40117ec5:0x3ffb27c0 0x401184ea:0x3ffb2800 0x4013509d:0x3ffb2820
#0 0x40084ee1:0x3ffb2570 in panic_abort at /Users/ficeto/Desktop/ESP32/ESP32S2/esp-idf-public/components/esp_system/panic.c:402
#1 0x4008e341:0x3ffb2590 in esp_system_abort at /Users/ficeto/Desktop/ESP32/ESP32S2/esp-idf-public/components/esp_system/esp_system.c:128
#2 0x40094709:0x3ffb25b0 in __assert_func at /Users/ficeto/Desktop/ESP32/ESP32S2/esp-idf-public/components/newlib/assert.c:85
#3 0x4008534a:0x3ffb26e0 in heap_caps_free at /Users/ficeto/Desktop/ESP32/ESP32S2/esp-idf-public/components/heap/heap_caps.c:360
(inlined by) heap_caps_free at /Users/ficeto/Desktop/ESP32/ESP32S2/esp-idf-public/components/heap/heap_caps.c:345
#4 0x40094739:0x3ffb2700 in free at /Users/ficeto/Desktop/ESP32/ESP32S2/esp-idf-public/components/newlib/heap.c:39
#5 0x400e9037:0x3ffb2720 in Segment::deallocateData() at wled00/FX_fcn.cpp:189
#6 0x400e917c:0x3ffb2740 in Segment::resetIfRequired() at wled00/FX_fcn.cpp:206
(inlined by) Segment::resetIfRequired() at wled00/FX_fcn.cpp:203
#7 0x400eaeeb:0x3ffb2760 in WS2812FX::service() at wled00/FX_fcn.cpp:1216 (discriminator 2)
#8 0x40117ec5:0x3ffb27c0 in WLED::loop() at wled00/wled.cpp:115 (discriminator 3)
#9 0x401184ea:0x3ffb2800 in loop() at C:/src/wled00/wled00.ino:20
#10 0x4013509d:0x3ffb2820 in loopTask(void*) at C:/Users/user/.platformio/packages/framework-arduinoespressif32/cores/esp32/main.cpp:50
ELF file SHA256: 18c20b536f4c6ef4
188956a4af