I'm getting a fatal error when I exit Stonefield Query Studio.

Add the following to Settings.xml in the Data subdirectory:

<setting name="Win7Mode" value="false" type="Boolean"/>

My project uses a 32-bit database so I have the IIS application pool set to 32-bit. However, when I run Stonefield Query, I get an HTTP error 500.19 - Internal Server Error.

The cause of this problem is that the 32-bit app domain is trying to load a 64-bit compression DLL, which is failing. The solution is to disable the compression (which unfortunately has to be a global change) or to install the 32-bit version of its DLL. To disable it, execute the following command:

%windir%\system32\inetsrv\appcmd.exe set config -section:system.webServer/httpCompression /-[name='xpress']

See http://forums.iis.net/t/1149768.aspx?500+19+Error+When+Enabling+32+bit+Application+Pool for more details and other suggestions.

I get this error when trying to load a project in Studio.

You likely downloaded a DLL used by Stonefield Query and that DLL is blocked. Select the DLL in Windows Explorer, right-click, choose Properties, and click the Unblock button in the Properties dialog.