Reproduction steps:
1. Open the attached file;
2. Build and Run the project on WebGL platform;
3. Build the project in the folder which name is with a space character, like New Folder.

Actual result: an error 'Uncaught incorrect header check' shows up in the browser. The project does not run in the browser, after closing an error.
Expected result: the project built on WebGL should run in the browser without any errors.

Note: An error shows up only when the project is built with a button 'Build and Run'. If the project is built simple with a button 'Build', everything works correctly.
The project built with 5.6.0b2 version shows a different error: 'Unexpected token < in JSON at position 0 '.
The web server can not read requests with a symbol %20 as a space character in the path.

Reproduced with: 5.5.0b10, 5.5.0p1, 5.6.0b2
Not reproducible: 5.4.0f1, 5.4.2f2, 5.5.0a1
Regression introduced in 5.5.0 beta

The bug reproduces in Chrome (Version 55.0.2883.87 (64-bit))(error_chrome.jpg), Firefox (Version 50.1.0) (error_firefox.jpg) and Microsoft Edge (Version 38.14393.0.0) browsers.