问题
For a couple of months i had no issue about generating the model from DB by deleting it and recreating it . After a pull from git, an issue has been occurred while trying to make the same process . After the second step (connection string creation with DB) there is no further proceed at the 3rd step and no connection string with the data base is being created at the app.config file.I have tried to test the connection with the database credentials and i am getting the following .
When i try to update specific tables from the model diagram as an alternative i get also the below :
System.Data.Entity.Core.EntityException: An error occurred while closing the provider connection. See the inner exception for details. ---> System.IO.FileNotFoundException: Could not load file or assembly 'System.Memory, Version=4.0.1.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies.
I have reinstalled Entity Framework and npgsql packages and tried to add all (the same) assemblies but with no success . Similar answers at Stack did not solve my issue . (I am allowed to work with the current versions with no further updates at VS or any of its packages.)
!Notice : i get all the appropriate data from my services when i use the API calls with the current model (proper communication with DB), but i cannot generate a new model from DB .
Any solutions ?
I am using
Windows 10
VS 2015
EntityFrameWork 6.2.0
Npgsql 3.1.1
.Net v.4.6.2
Asp.net
Thanks in advance !
回答1:
Use IL Disassembler (ildasm.exe) to check if the version in your output directory matches the one in the error message.
Our software often runs into these kind of problems because different nuget packages require different versions together with a nasty mix of libraries not in nuget.
The need for different versions of the same library is not considered by the build process.
If the version mismatch is really the cause of your problem, you may be looking for binding redirects in you app.config to forward all older versions of that library to the newest one.
Something like this will need to be added to the <dependentAssembly> node of the library in question:
<bindingRedirect oldVersion="0.0.0.0-4.2.0.0" newVersion="4.2.0.0" />
ildasm can usually be found here (depending on your Visual Studio version)
C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A\bin\NETFX 4.5.1 Tools\ildasm.exe
回答2:
Actually this answer come from a senior and he just helped to solve it! He said because the solution keep the old files -> this error, you can try to open each projects of solution and then remove folders 'bin' and 'obj' -> clean build again! Just an option you can try!
回答3:
I just had a similar problem with a console app I'm working on. It was working fine last night. Today I got the error message "Could not load file or assembly 'System.Memory, Version=4.0.1.0...". I wasn't able to resolve this until I went into Configuration Manager for my Visual Studio Solution and changed Active solution platform from "Any CPU" to "x64". After rebuilding my program now works and no longer throws the exception.
回答4:
For some reasons, the specific nugget package was not installed properly and I had not the option to compare it with an older file because I had messed up the backup file. I cloned the repository again(even if I had to discard some progress).
Steps:
I had .Net version issues by downloading via nugget package manager so I had to do it manually.
I have downloaded the .nupkg file from https://www.nuget.org/packages/System.Memory/
Extracted the dll with a batch file found in https://gist.github.com/fex80/976ff887acb825171de6
Copied to the bin folder of the proper project .
Rebuild the project and at last, it worked.
回答5:
From a quick google search I found this : https://github.com/GrillPhil/ServerlessRealtimeDemo/issues/1
I don't know if this is out to date, but have you tried setting your Target version to Windows 10, version 1803 (10.0; Build 17134) and Min version to Windows 10 Fall Creators Update (10.0; Build 16299) in your project properties?
来源：https://stackoverflow.com/questions/55509638/could-not-load-file-or-assembly-system-memory-version-4-0-1-in-visual-studio