We had just launched our redeveloped site yesterday. Today, after making a few changes to some XSL (minor edits) I was unable to get back into the members or developer sections of the site. I receive the following messages within the back office:

Server error: Contact administrator, see log for full details.
Failed to retreive data for application tree member

Server error: Contact administrator, see log for full details.
Failed to retreive data for application tree developer

And all that is getting logged is this:

2014-01-30 09:29:12,149 [6] INFO  Umbraco.Core.PluginManager - [Thread 47] Starting resolution types of Umbraco.Web.Trees.TreeController
2014-01-30 09:29:12,149 [6] INFO  Umbraco.Core.PluginManager - [Thread 47] Completed resolution of types of Umbraco.Web.Trees.TreeController, found 4 (took 0ms)

The following page resource is failing when I attempt to navigate to the developer section:

Failed to load resource: the server responded with a status of 500 (Internal Server Error) http://www.DOMAIN.com/umbraco/UmbracoTrees/ApplicationTree/GetApplicationTrees?application=member&tree=&isDialog=false

Which is generating this content when I navigate to the URL:

)]}',
{"Message":"An error has occurred."}

Additionally, since we changed environments to production--I noticed many of the buttons and labels are getting bracketed text (ex: [general_actions]) rather than the actual text in the back office?

Any help is greatly appreciated! I am not sure if I just need to upgrade it to one of the more recent 7.X releases or not.