When pressing the "Start" button repeatedly and in quick successions, the application encounters an unhandled exception and displays this warning:

The full details are as follows:
See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.InvalidOperationException: This BackgroundWorker is currently busy and cannot run multiple tasks concurrently.
at System.ComponentModel.BackgroundWorker.RunWorkerAsync(Object argument)
at SLAM.Form1.StartPoll()
at SLAM.Form1.StartButton_Click(Object sender, EventArgs e)
at System.Windows.Forms.Control.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.ButtonBase.WndProc(Message& m)
at System.Windows.Forms.Button.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

************** Loaded Assemblies **************
mscorlib
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2101.1 built by: NET47REL1LAST
CodeBase: file:///C:/Windows/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll

SLAM
Assembly Version: 1.5.4.0
Win32 Version: 1.5.4.0
CodeBase: file:///C:/Users/Daniel/Documents/2017/Programs/SLAM/SLAM.exe

Microsoft.VisualBasic
Assembly Version: 10.0.0.0
Win32 Version: 14.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.VisualBasic/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll

System
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll

System.Core
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll

System.Windows.Forms
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll

System.Drawing
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll

System.Configuration
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll

System.Xml
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll

System.Runtime.Remoting
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Remoting/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll

System.Net.Http
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Net.Http/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Net.Http.dll

System.Runtime.Serialization
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Runtime.Serialization/v4.0_4.0.0.0__b77a5c561934e089/System.Runtime.Serialization.dll

SMDiagnostics
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/SMDiagnostics/v4.0_4.0.0.0__b77a5c561934e089/SMDiagnostics.dll

System.ServiceModel.Internals
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ServiceModel.Internals/v4.0_4.0.0.0__31bf3856ad364e35/System.ServiceModel.Internals.dll

Accessibility
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Accessibility/v4.0_4.0.0.0__b03f5f7f11d50a3a/Accessibility.dll

System.Management
Assembly Version: 4.0.0.0
Win32 Version: 4.7.2053.0 built by: NET47REL1
CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Management/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Management.dll

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (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:

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