Could not load file or assembly 'System.Threading.Tasks.Extensions, Version=


I recently installed CsvHelper ( when i try to use the library I get the following error:

Could not load file or assembly 'System.Threading.Tasks.Extensions, Version=, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

In my app.config I have binding redirect:

            <assemblyIdentity name="System.Threading.Tasks.Extensions" publicKeyToken="cc7b13ffcd2ddd51" culture="neutral" />
            <bindingRedirect oldVersion="" newVersion="" />

Also in my project I have reference to


Its version is I am not sure why its still trying to load of the library.

my project is running .net 4.7.2

asked on Stack Overflow Feb 12, 2020 by Ismail

2 Answers


So i created a new .net 472 project then added all the libs etc and code and now it works.

I suspect it originally broke because I had installed a really old version of csvhelper lib with excel plugin. Even though i removed it and removed all references it was still picking it up from somewhere.

answered on Stack Overflow Feb 13, 2020 by Ismail

According to this seems to be a bug in one of the CSVHelper 15.0.0 dependencies. The 15.0.0 version (not sure about earlier ones) brings in some other assembly which causes the problem.

Personally I worked around this by downgrading to 13.0, but that bug report now states that they have released 15.0.1 specifically to fix this. I've yet to confirm that myself.

answered on Stack Overflow Mar 6, 2020 by UuDdLrLrSs • edited Mar 7, 2020 by UuDdLrLrSs

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