Request Error - Posting HTML to a WCF via jQuery

I created a simple WCF service for handling jQuery calls (RESTful). The service was handling data from the website one of which was raw HTML. The HTML was sanitized on the server before being saved in a database. However, whenever I made a call to the server, it greeted me with the iconic error: Request Error....

The process cannot access the file '' because it is being used by another process

I was building a simple web system which relied on XML files. On initiation, the system would open the XML config file, read it and include other XML files defined in it:

The operation was done within a WebForm and it worked just fine. I also had a WCF service whose job was to...