Exception error after upgrade dev express

After change dev express DLL in Bin directory from dev express 16.2 to 20.2 i got this error :

put all dev express dll in Bin folder and change and fix reference from web.config

Could not load file or assembly 'DevExpress.Data.v20.2' or one of its dependencies. Strong name signature could not be verified.  The assembly may have been tampered with, or it was delay signed but not fully signed with the correct private key. (Exception from HRESULT: 0x80131045

LOG: DisplayName = DevExpress.Data.v20.2 (Partial) WRN: Partial binding information was supplied for an assembly: WRN: Assembly Name: DevExpress.Data.v20.2 | Domain ID: 3 WRN: A partial bind occurs when only part of the assembly display name is provided. WRN: This might result in the binder loading an incorrect assembly. WRN: It is recommended to provide a fully specified textual identity for the assembly, WRN: that consists of the simple name, version, culture, and public key token. WRN: See whitepaper http://go.microsoft.com/fwlink/?LinkId=109270 for more information and common solutions to this issue. LOG: Appbase = file:///D:/Alavi/StuFood/StuFood New/ LOG: Initial PrivatePath = D:\Alavi\StuFood\StuFood New\bin Calling assembly : (Unknown