Cannot load assembly while installing a package

I’ve created a custom activity in Visual studio using UiPath Activity Creator. In this activity I’m working with Entity Framework core and connecting with database. I publish my project successfully and when I try to install this package in UiPath It says following package cannot be installed and showed following error in logs:

Cannot load assembly: C:\Users\maryum.siddique.nuget\packages\MyActivity.Test.activities/\lib/net461/Microsoft.EntityFrameworkCore.dll : System.TypeLoadException: Method ‘DisposeAsync’ in type ‘Microsoft.EntityFrameworkCore.DbContext’ from assembly ‘Microsoft.EntityFrameworkCore, Version=, Culture=neutral, PublicKeyToken=adb9793829ddae60’ does not have an implementation.

I have no idea what’s the issue. Can anyone help with this?


I have the same issue. I will solve it and keep you updated. :wink:

1 Like

Hi, just check out this article:


it seems to be an issue with the Package you are using in your custom activity which is already used by UiPath. Just try to install Microsoft.EntityFrameworkCore.DbContext above the UiPath package manager and observe if the issue occurs again.

Did you get your issue resolved?

Did you package that DLL in your project?

Yes I did.

Maybe remove it then or make sure you are using the same version as already on the server.

Yes I solved it by using a different assembly. In my case the error occured with System.Text.JSON. So I just used Newtonsoft.Json. (Unable to install System.text.json package)