At shutdown of FSX I received the following...Running the current version of FSUIPC 4.949p with FSX Acceleration (Boxed) 
  
 
 
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
  <Provider Name="Application Error" />
  <EventID Qualifiers="0">1000</EventID>
  <Level>2</Level>
  <Task>100</Task>
  <Keywords>0x80000000000000</Keywords>
  <TimeCreated SystemTime="2016-04-20T19:56:20.000000000Z" />
  <EventRecordID>100885</EventRecordID>
  <Channel>Application</Channel>
  <Computer>udidwht-PC</Computer>
  <Security />
  </System>
- <EventData>
  <Data>fsx.exe</Data>
  <Data>10.0.61637.0</Data>
  <Data>46fadb14</Data>
  <Data>FSUIPC4.dll_unloaded</Data>
  <Data>0.0.0.0</Data>
  <Data>5715e438</Data>
  <Data>c0000005</Data>
  <Data>5e78e246</Data>
  <Data>1a10</Data>
  <Data>01d19b3988a263e7</Data>
  <Data>D:\Flight Simulator X\fsx.exe</Data>
  <Data>FSUIPC4.dll</Data>
  <Data>f31abe22-0731-11e6-9c32-50e5495c0441</Data>
  </EventData>
  </Event>