title: Conflict for System.Runtime.CompilerServices.Unsafe between Npgsql and System.Threading.Tasks.Extensions
body: <p>I have downloaded EntityFramework6.Npgsql 6.4.0 nuget.
  As a dependent, Npgsql 4.1.2 was installed along with the nuget.</p>
  
  <p>While running the code, observed following error:</p>
  
  <pre><code>=== Pre-bind state information === LOG: DisplayName = **System.Runtime.CompilerServices.Unsafe, Version=4.0.5.0**, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a  (Fully-specified) LOG: Appbase = file:///C:/Program Files (x86)/Agilent Technologies/Sample Scheduler for OpenLab/Bin/ LOG: Initial PrivatePath = NULL Calling assembly : Npgsql, Version=4.1.2.0, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7.
  === LOG: This bind starts in default load context. LOG: No application configuration file found. LOG: Using host configuration file:  LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config. LOG: Post-policy reference: System.Runtime.CompilerServices.Unsafe, Version=4.0.5.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a LOG: Attempting download of new URL file:///C:/Program Files (x86)/X/Y/Bin/System.Runtime.CompilerServices.Unsafe.DLL. WRN: Comparing the assembly name resulted in the mismatch: Revision Number ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.
  </code></pre>
  
  <p>To fix this, I have copied the System.Runtime.CompilerServices.Unsafe, Version=4.0.5.0 into my Bin directory.</p>
  
  <p>After this, I got the following error:</p>
  
  <pre><code>=== Pre-bind state information === LOG: DisplayName = **System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1**, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a  (Fully-specified) LOG: Appbase = file:///C:/Program Files (x86)/Agilent Technologies/Sample Scheduler for OpenLab/Bin/ LOG: Initial PrivatePath = NULL Calling assembly : System.Threading.Tasks.Extensions, Version=4.2.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51.
  === LOG: This bind starts in default load context. LOG: No application configuration file found. LOG: Using host configuration file:  LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v4.0.30319\config\machine.config. LOG: Post-policy reference: System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a LOG: Attempting download of new URL file:///C:/Program Files (x86)/X/Y/Bin/System.Runtime.CompilerServices.Unsafe.DLL. WRN: Comparing the assembly name resulted in the mismatch: Revision Number ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.
  </code></pre>
  
  <p>Due to this incompatible dependency on the same library with different versions, I could not go forward.</p>
  
  <p>Please help, how to fix this.</p>