Blank Page with the word 'error' on it

Hi I have recently taken over a project using modx evolution. When I load the site i receive a blank white page with the word error in the upper left hand corner. I checked the error logs but they don't mention anything. Its an internal 500 error. Has anyone else experienced this?

i just previewed the site in the manager and it gives me this error.

MODX encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »
PHP error debug
Error : Invalid argument supplied for foreach()
ErrorType[num] : WARNING[2]
File : /home1/oomit/public_html/manager/includes/document.parser.class.inc.php
Line : 1405
Source : foreach ($this->documentMap as $document) {
Basic info
REQUEST_URI : /
Resource : [1]Home
Current Snippet : Wayfinder
Referer : http://www.oilfield.omron.com/manager/index.php?a=1&f=menu
User Agent : Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
IP : 50.249.89.197
Benchmarks
MySQL : 0.1922 s (22 Requests)
MySQL : 0.1922 s (22 Requests)
PHP : 0.1112 s
Total : 0.3034 s
Memory : 2.02337646484 mb

Backtrace
1 DocumentParser->executeParser()
index.php on line 135
2 DocumentParser->prepareResponse()
manager/includes/document.parser.class.inc.php on line 1288
3 DocumentParser->parseDocumentSource()
manager/includes/document.parser.class.inc.php on line 1368
4 DocumentParser->evalSnippets()
manager/includes/document.parser.class.inc.php on line 1180
5 DocumentParser->_get_snip_result()
manager/includes/document.parser.class.inc.php on line 868
6 DocumentParser->evalSnippet()
manager/includes/document.parser.class.inc.php on line 952
7 eval()
manager/includes/document.parser.class.inc.php on line 823
8 Wayfinder->run()
manager/includes/document.parser.class.inc.php(823) : eval()'d code on line 92
9 Wayfinder->getData()
assets/snippets/wayfinder/wayfinder.inc.php on line 46
10 DocumentParser->getChildIds()
assets/snippets/wayfinder/wayfinder.inc.php on line 310

I had the same message after upgrading to the latest version, turned out that not all the files had uploaded via ftp. Re-uploaded the files via a different ftp program and the problem was fixed.