The application ran fine the first couple of times I ran it. Now, out of the blue, I'm getting unhandled exception:

System.ArgumentException: Invalid parameter used.
at System.Drawing.Bitmap..ctor(String filename)
at VSPlayNET.Form1.listBox1_SelectedIndexChanged(Object sender, EventArgs e)
at System.Windows.Forms.ListBox.OnSelectedIndexChanged(EventArgs e)
at System.Windows.Forms.ListBox.set_SelectedIndex(Int32 value)
at VSPlayNET.Form1.refreshCardList()
at VSPlayNET.Form1.newDeck()
at VSPlayNET.Form1.Form1_Load(Object sender, EventArgs e)
at System.Windows.Forms.Form.OnLoad(EventArgs e)
at System.Windows.Forms.Form.OnCreateControl()
at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
at System.Windows.Forms.Control.CreateControl()
at System.Windows.Forms.Control.WmShowWindow(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
at System.Windows.Forms.ContainerControl.WndProc(Message& m)
at System.Windows.Forms.Form.WmShowWindow(Message& m)
at System.Windows.Forms.Form.WndProc(Message& m)
at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/microsoft.net/framework/v1.1.4322/mscorlib.dll
----------------------------------------
VSPlayNET
Assembly Version: 1.0.1650.16951
Win32 Version: 1.0.1650.16951
CodeBase: file:///C:/Program%20Files/VSed/VSPlayNET.exe
----------------------------------------
System.Windows.Forms
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.windows.forms/1.0.5000.0__b77a5c561934e089/system.windows.forms.dll
----------------------------------------
System
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system/1.0.5000.0__b77a5c561934e089/system.dll
----------------------------------------
System.Data
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.data/1.0.5000.0__b77a5c561934e089/system.data.dll
----------------------------------------
System.Drawing
Assembly Version: 1.0.5000.0
Win32 Version: 1.1.4322.573
CodeBase: file:///c:/windows/assembly/gac/system.drawing/1.0.5000.0__b03f5f7f11d50a3a/system.drawing.dll
----------------------------------------

************** JIT Debugging **************
To enable just in time (JIT) debugging, the config file for this
application or machine (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
<system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the machine
rather than being handled by this dialog.

Seems like it's not able to load the images or database properly. Try uninstalling, deleting the VSed direcotry and then download the newest one from these forums and install agian.

I just did that. No change. I guess I'm going to have to reinstall everything from scratch.

Which version are you using? The one that only runs w/MTGPlay or the standalone? I would recommend using the standalone since it'll save you some trouble.