Trouble with upload Documents

[Toberius]

I install fengoffice_2.2.0rc.zip.

Add change at php.ini file:
max_execution_time = 600
post_max_size = 30M
upload_max_filesize = 30M
memory_limit=64

When I wanted to upload document saw this error: Missing lang.js information: Error 500: Internal server error.

MySQL log type this:
[Fri Oct 19 00:20:45 2012] [error] [client xxxxxxx] PHP Fatal error:  Call to undefined function hash_file() in application/models/project_files/ProjectFile.class.php on line 353, referer:

[jirib]

No idea but can PHP write to upload directory? Check its permission so PHP (if standalone process or webserver when using mod_php) can write there.