Hi!
Thank you for your response! Unfortunately these solutions didn’t work.
In Resources tab, I didn’t find the way to force the image files to preload (I guess they are preloaded anyway). For audio files there are three different options for preloading.
I made the separate loading scene, which is between the start scene and the game scene. However I noticed, that the game didn’t even try to load anything during the load screen.
With Firefox Network inspecting tool I finally managed to figure out, what is going on. You were right, the problem is really on the web hotel provider side. The screenshot below shows the core of the problem:
First the browser succeeds to load images, but suddenly the server starts to return 403 (forbidden) error. Also the error log of of the web hotel (cPanel) shows the error: “Client denied by server configuration”.
Googling revealed, that most likely the web hotel has the protection mechanism for Denial-of-Service (DoS) attacks, here an attacker will make lots of requests to the site, hoping to use up all of CPU and memory resources and stop the site working and denying service to legitimate users. To prevent DoS attacks, server allows only the certain number of requests to the same page during certain time period.
The protection mechanism itself is good, but in the case of the game having hundreds of objects (which is typical, if you have several characters having animations for idle, walk, run, jump, crawl, climb etc.) the mechanism turns against you.
I’ll contact web hotel server provider and try to find out whether there are some ways to suppress protection mechanism (e.g. with .htaccess configuration). If there is a way, I’ll put it also here, because altough this was not a bug of GDevelop, also other users may confront the same problem and this will serve as a documentation of the problem, cause and (possible) solution.