Stuck at rebuilding all screens

Bugs
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1

I am very new to HMI development, LVGL and squareline studio. when i was trying to run example, window get stuck at rebuilding all screens. I tried many examples and i got same behaviour. i tried refresh all screen option from themes but did not work. I am planning to use elecrow display.

OS: Ubuntu 25.
Squareline Studio: SquareLine_Studio_Linux_v1_5_4. I observed following log on Console tab,

Try to start lvgl server on port: 20085
Try to start lvgl server on port: 20085
Try to start lvgl server on port: 20085

sdev@sdev:~/lvgl_development/SquareLine_Studio_Linux_v1_5_4$ ./SquareLine_Studio.x86_64 
[UnityMemory] Configuration Parameters - Can be set up in boot.config
    "memorysetup-bucket-allocator-granularity=16"
    "memorysetup-bucket-allocator-bucket-count=8"
    "memorysetup-bucket-allocator-block-size=4194304"
    "memorysetup-bucket-allocator-block-count=1"
    "memorysetup-main-allocator-block-size=16777216"
    "memorysetup-thread-allocator-block-size=16777216"
    "memorysetup-gfx-main-allocator-block-size=16777216"
    "memorysetup-gfx-thread-allocator-block-size=16777216"
    "memorysetup-cache-allocator-block-size=4194304"
    "memorysetup-typetree-allocator-block-size=2097152"
    "memorysetup-profiler-bucket-allocator-granularity=16"
    "memorysetup-profiler-bucket-allocator-bucket-count=8"
    "memorysetup-profiler-bucket-allocator-block-size=4194304"
    "memorysetup-profiler-bucket-allocator-block-count=1"
    "memorysetup-profiler-allocator-block-size=16777216"
    "memorysetup-profiler-editor-allocator-block-size=1048576"
    "memorysetup-temp-allocator-size-main=4194304"
    "memorysetup-job-temp-allocator-block-size=2097152"
    "memorysetup-job-temp-allocator-block-size-background=1048576"
    "memorysetup-job-temp-allocator-reduction-small-platforms=262144"
    "memorysetup-allocator-temp-initial-block-size-main=262144"
    "memorysetup-allocator-temp-initial-block-size-worker=262144"
    "memorysetup-temp-allocator-size-background-worker=32768"
    "memorysetup-temp-allocator-size-job-worker=262144"
    "memorysetup-temp-allocator-size-preload-manager=262144"
    "memorysetup-temp-allocator-size-nav-mesh-worker=65536"
    "memorysetup-temp-allocator-size-audio-worker=65536"
    "memorysetup-temp-allocator-size-cloud-worker=32768"
    "memorysetup-temp-allocator-size-gfx=262144"
Segmentation fault (core dumped)

I tried latest version on windows, but after installation, application was not launching.

Here is the screenshot of the application running on ubuntu,

image
image1857×1055 139 KB

2

i gave chmod +x to all directory and started working.

3

Hi, you are exactly right. The issue was related to permissions. SquareLine Studio uses a separate background process (the “lvgl server” or simulator, which is often based on MicroPython) to render the screen previews.

The logs you provided (“Try to start lvgl server…” repeatedly, followed by a “Segmentation fault”) strongly suggested that the main application didn’t have the necessary execute permissions (+x) to launch this external simulator program.

By running chmod +x on the necessary files/directories, you granted the required permissions, allowing the backend simulator to start correctly. We’re glad you got it working!