php日志中的奇怪字符

I'm tring to install phalcon framework on my server, which is supposed to be quite easy:

1. Add php_phalcon.dll in extensions dir
2. Add `extension = php_phalcon.dll 'to php.ini
3. Restart the server

But for some reason the extension can not be loaded. And I can not get the reason because warning messages in the log file appear like this: [03-Dec-2017 17:12:39 UTC] PHP Warning: PHP Startup: Unable to load dynamic library 'C:\Program Files\PHP\v7.1\ext\php_phalcon.dll' - �� ������ �������� �����. in Unknown on line 0 How can I make log messages become readable?

Additional information might be useful:

• OS: Windows Server 2008 R2 (x64)
• IIS 7
• PHP: I tried two versions: 5.6 (x86) and 7.1 (x64)