Linqpad not able to load the driver

Jul 8, 2013 at 3:48 AM
Followed the instructions in the documentation
Linqpad displays the message that Driver successfully updated. When browsed to the connections it shows an error "Error(s) were reported loading third-party providers"

Error instantiating type Tx.LinqPad.TxDataContextDriver in C:\ProgramData\LINQPad\Drivers\DataContext\4.0\Tx.LinqPad (3d3a4b0768c9178e)\Tx.LinqPad.dll
  • Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
Jul 8, 2013 at 5:10 AM
Recently there was an issue with the signature of the XEvent assemblies, which was fixed in build 1.0.30627

To see if this is the problem, go to the above directory and run: sn -v Microsoft.SqlServer.XEvent.Linq.dll
If it says "... is a delay-signed or test-signed assembly", you should try installing the latest build.

If this does not fix the problem, please try the Troubleshooting wiki:

Jul 18, 2014 at 7:37 PM
I just experienced the same issue - even after installing the latest Tx.LingPad build.

Also running the sn command I see the dll looks fine. I get:
C:\ProgramData\LINQPad\Drivers\DataContext\4.0\Tx.LinqPad (3d3a4b0768c9178e)>sn -v Microsoft.SqlServer.XEvent.Linq.dll

Microsoft (R) .NET Framework Strong Name Utility  Version 4.0.30319.18020
Copyright (c) Microsoft Corporation.  All rights reserved.

Assembly 'Microsoft.SqlServer.XEvent.Linq.dll' is valid

C:\ProgramData\LINQPad\Drivers\DataContext\4.0\Tx.LinqPad (3d3a4b0768c9178e)>
Jul 21, 2014 at 4:23 PM
Actually, this is not a problem always. See
Feb 23, 2015 at 8:54 AM
Is Microsoft.SqlServer.XEvent.Linq.dll redistrubutable..?

Feb 23, 2015 at 8:27 PM
I think it is redistributable. Good place to ask is in the XEvent blog:
Feb 25, 2015 at 6:43 AM
Thanks for the link George. However, I was wondering if Microsoft.SqlServer.XEvent.Linq.dll is a doubtful redistributable then tx itself is not fully Apache License 2.0 license.. I may have to use only the parts where the xevent.linq.dll is not used.. I looked at different resources in the web but none gives a clear picture w.r.t license of this dll.
BTW, tx is wonderful..

May 15, 2015 at 12:04 AM

The latest distribution of the tx driver doesn't contain Microsoft.SqlServer.XEvent.Linq. I don't have SQL server installed and I'm only using Tx for ETW log analysis in LinqPad. Is there any way to

a) Remove that dependency;
b) Provide that assembly along with the rest of the xevent assemblies.

This is a list of files that I currently have in the Tx directory:

Directory of c:\ProgramData\LINQPad\Drivers\DataContext\4.0\Tx.LinqPad (3d3a4b0768c9178e)

05/14/2015 03:21 PM <DIR> .
05/14/2015 03:21 PM <DIR> ..
02/07/2015 01:32 PM 393,216 BasicPerfCounters.blg
02/07/2015 01:32 PM 557,056 CrossMachineHTTP.etl
02/07/2015 01:32 PM 7,249,920 CrossMachineIE.etl
02/07/2015 01:32 PM 133 header.xml
02/07/2015 01:32 PM 294,912 HTTP_Server.etl
02/07/2015 01:32 PM 63,198
02/07/2015 01:32 PM 124,481
02/07/2015 01:32 PM 95,848 Microsoft.SqlServer.XE.Core.dll
02/07/2015 01:32 PM 223,848 Microsoft.SqlServer.XEvent.Configuration.dll
02/07/2015 01:32 PM 224,872 Microsoft.SqlServer.XEvent.dll
02/07/2015 01:32 PM 121,960 Microsoft.SqlServer.XEvent.Targets.dll
02/07/2015 01:32 PM 724,332
02/07/2015 01:32 PM 773,968 msvcr100.dll
02/07/2015 01:32 PM 5,242,880 SampleWcfTrace.etl
02/07/2015 01:32 PM 9,728 sqltrace.xel
02/07/2015 01:32 PM 104,680 System.Reactive.Core.dll
02/07/2015 01:32 PM 24,296 System.Reactive.Interfaces.dll
02/07/2015 01:32 PM 704,232 System.Reactive.Linq.dll
02/07/2015 01:32 PM 38,120 System.Reactive.PlatformServices.dll
02/07/2015 01:32 PM 25,832 System.Reactive.Windows.Forms.dll
04/10/2015 07:09 AM 41,472 Tx.Core.dll
04/10/2015 07:09 AM 37,888 Tx.LinqPad.dll
04/10/2015 07:09 AM 12,288 Tx.SqlServer.dll
04/10/2015 07:09 AM 77,824 Tx.Windows.dll
04/10/2015 07:09 AM 34,304 Tx.Windows.TypeGeneration.dll
02/07/2015 01:32 PM 583,272 xe.dll

May 15, 2015 at 2:06 AM

As a temporary workaround please:
I am working to figure out why it is not included.

May 15, 2015 at 11:41 AM
Please try the fix in 1.0.50514.

May 15, 2015 at 9:30 PM
Thanks, I got the dll with the update (much appreciated), but I'm still hitting the original problem that brought me here:

(From Linqpad):

Error instantiating type Tx.LinqPad.TxDataContextDriver in C:\ProgramData\LINQPad\Drivers\DataContext\4.0\Tx.LinqPad (3d3a4b0768c9178e)\Tx.LinqPad.dll
  • Could not load file or assembly 'file:///C:\ProgramData\LINQPad\Drivers\DataContext\4.0\Tx.LinqPad (3d3a4b0768c9178e)\Tx.SqlServer.dll' or one of its dependencies. An attempt was made to load a program with an incorrect format.
1) I checked that all my assemblies are matching bitness (32bit);
2) fuslogvw is not able to give me any meaningful related information. I do get a couple of bind failures for these assemblies:


all because they're neither in the GAC nor on the file system.

Other data sources in LinqPad work so I'm pretty sure it's not a problem with e.g. an assembly that's responsible for loading third party plugins. I'll check again the Tx.SqlServer.dll dependency list to see if I can track a missing dependency down the tree. Wondering why fuslogvw is not logging the failure.

Thanks again,
May 17, 2015 at 12:43 AM

Unfortunately I can't reproduce the problem. Our machines are Windows 8.1 or Server 2012.
It does not look as .Net issue.

As far as I understand it:
  • XEvent.*. dll are wrappers of the native XEvent engine (xe.dll)
  • xe.dll must be in the same directory. I picked only the 32bit as more common.
  • in the past I had issues chasing its dependencies like msvcr100.dll
Are you by any chance using x64 LINQPad? And what is your OS?

You can also try removing everything XEvent and building Tx as in the Troubleshooting page

Jun 30, 2015 at 10:08 PM
Update - gave it a shot again today and was able to get it to work with the latest linqpad driver and linqpad itself. Haven't had a chance to go back and look at the changelogs, but I assume the problem was fixed on either the linqpad side, or the tx driver side.

Thanks Georgi.