server event dll issue

Hello, I'm a new user to the Aras solution and still trying to get my head round a number of things. The installation I did myself. The first action that I would like to do is to create my own part numbering solution. I have created a new List that will form part of the Part Number and then created the following line for the server event on the Part Item Type:

me.setProperty("item_number") = me.getProperty("project_id") & "-" & me.getInnovator.getNextSequence("Default Part")

The issue is when I come to compile the line, I get the following error and the *.dll changes each time:

Could not find file 'C:\Program Files (x86)\Aras\Innovator\Innovator\Server\dll\3000xrxd.dll'.

The dll folder is empty. What have I missed? I appreciate any help or advice that you can give. Thanks