As per the exception you pasted, UAC isn't allowing icomancer to save its own settings file.

Please run icomancer as administrator (even if you are an administrator). That should fix it.

System.UnauthorizedAccessException: Access to the path 'C:\ProgramData\LAVA SoftWorks\icomancer\Onscreen Settings.xml' is denied.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean useAsync)
at System.Xml.XmlWriterSettings.CreateWriter(String outputFileName)
at System.Xml.XmlWriter.Create(String outputFileName, XmlWriterSettings settings)
at System.Xml.Linq.XElement.Save(String fileName, SaveOptions options)
at Icomancer.Functions.SaveOnScreenSettings(Boolean IgnoreSkeletonSaving) in H:\Icomancer\Icomancer\Functions.vb:line 2529
at Icomancer.modAppOps.CheckForUpdates(Boolean CallingFromOpenedForm) in H:\Icomancer\Icomancer\modAppOps.vb:line 592
at Icomancer.frmLauncher.CheckForUpdates() in H:\Icomancer\Icomancer\frmLauncher.vb:line 86
at Icomancer.frmLauncher.frmLauncher_Shown(Object sender, EventArgs e) in H:\Icomancer\Icomancer\frmLauncher.vb:line 79
at System.Windows.Forms.Form.OnShown(EventArgs e)
at System.Windows.Forms.Form.CallShownEvent()
at System.Windows.Forms.Control.InvokeMarshaledCallbackDo(ThreadMethodEntry tme)
at System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Forms.Control.InvokeMarshaledCallback(ThreadMethodEntry tme)
at System.Windows.Forms.Control.InvokeMarshaledCallbacks()

Please take a screen shot of this and send it to icomancer_support@lavasoftworks.com so we can figure out how to fix it.