asp server error ' Could not load file or assembly ' but the assembly is definitely there.

Question

I am currently getting the following error. On a locahost website.

Could not load file or assembly 'MySql.Data, Version=6.5.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

Though, the reference is definitely there in the references folder and that dll is definitely on my local machine in the place it is pointing to. I have also tried deleting and re-adding the reference.

Does anyone know what would cause this error?

Also what is the assemblys manifest definition?

Thanks in advance for the help, I very much appreciate it.

Solution 1

in visual studio select the reference in the solution explorer then in the properties make sure the Specific Version property is set to false.

If you have an entry for this reference in the web.config, edit the file and remove the version information.

if you close visual studio and open the project file with a text editor, make sure in the project file the version of the assembly is not listed but only the name and type, so just remove the following:

, Version=6.5.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d'

then it should work no matter if you are using the 6.5.5 or 6.5.4, as long as the code is using classes and methods available in both.

Solution 2

I have experienced the same situation and managed to fix the problem with these steps,

Read the error information carefully which provides helpful details to rectify the situation. I wouldn't change the machine.config file. As it says Application cannot find a reference to the assembly MySql.Web and the version it is trying to reference is Version=6.7.4.0.

Based on path you install MySql you will be able to find the correct assembly files, ex :

C:\Program Files\MySQL\Connector NET 6.7.4\Assemblies\v4.0\MySql.Data.dll

Copy that file to bin folder. (I would copy all the files in C:\Program Files\MySQL\Connector NET 6.7.4\Assemblies\v4.0\ folder to bin folder)

Hope this helps! Thanks