You can check the Web Console for relevant messages.

• "3-bar" menu button or Tools -> Web Developer
• https://developer.mozilla.org/en-US/Tools/Web_Console

If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block content (Adblock Plus, NoScript, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block content.

• make sure your extensions and filters are updated to the latest version
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Firefox shows a purple instead of a gray shield icon at the left end of the location/address bar in case Tracking Protection is blocking content. You can click shield icon for more detail and possibly disable the protection. You can check the Web Console for messages about blocked content.

• https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop

You can try these steps in case of issues with web pages:

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

• hold down the Shift key and left-click the Reload button
• press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
• press "Command + Shift + R" (Mac)

Clear the Cache and remove the Cookies for websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Remove the Cookies" for websites that cause problems:

• Options/Preferences -> Privacy & Security
  Cookies and Site Data: "Manage Data"

"Clear the Cache":

• Options/Preferences -> Privacy & Security
  Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem.

• switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Safe Mode start window

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Thank you for reply. I used your recipes, but there is no good result. I turned off all extensions (adblock, NoScript and other), tracking protection for this site, but the view didn't change. After that I restart browser in safe mode and took "use browser with webgl support" (don't remember exactly).

In web console I see many warning and errors, but I'm not web developer or programmer, so I can't understand its. However, I opened the same page on another computer, also with Windows 7 and Firefox, and everything is displayed well there. There are many errors and warnings too, but there is no this:

"THREE.WebGLRenderer: WEBGL_depth_texture extension not supported. jquery.min.js line 4 > eval:651:242024

THREE.WebGLRenderer: OES_texture_float_linear extension not supported."

I tried to find answer in Google and Yandex, but its not helpful.

Right. These errors are suspicious.

Enter about:support in the URL bar and search for OES_texture_float_linear and WEBGL_depth_texture in the WebGL 1 Extensions section.

There are no in the section those statements. There are only this:

"ANGLE_instanced_arrays EXT_blend_minmax EXT_color_buffer_half_float EXT_float_blend EXT_frag_depth EXT_shader_texture_lod EXT_texture_filter_anisotropic MOZ_debug OES_element_index_uint OES_standard_derivatives OES_texture_float OES_texture_half_float OES_texture_half_float_linear OES_vertex_array_object WEBGL_color_buffer_float WEBGL_compressed_texture_s3tc WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_lose_context"

What's the webgl 1 driver renderer and version?

WebGL 1 Driver Renderer Google Inc. -- ANGLE (NVIDIA Quadro FX 1500 Direct3D9Ex vs_3_0 ps_3_0)

WebGL 1 Driver Version OpenGL ES 2.0.0 (ANGLE 2.1.0.eabf2a79aac3)

Meanwhile, I found an interesting record:

WebGL 2 Driver Renderer WebGL creation failed:

• tryANGLE
• Exhausted GL driver options.