In my most recent blog, I extensively covered the steps involved in configuring a Visual Studio Solution for Sitecore development . Following the publishing process, I came across an error message that read " could not load file or assembly 'system.web.mvc, version=5.2.4.0 ," as visibly shown above. The root of the problem was traced back to a discrepancy between my Visual Studio solution, which was utilizing version 5.2.7.0 of 'system.web.mvc,' and the Sitecore Instance, which was employing version 5.2.4.0. To successfully address this issue, I adopted a straightforward solution: Copied the ' system.web.mvc.dll ' and ' system.web.mvc xml' from my backed-up " C:\inetpub\wwwroot\sc103sc.dev.local - Copy\bin" folder. Pasted to Visual Studio solution " C:\Users\ilma\source\repos\MySitecoreDemo\MySitecoreDemo\bin " and updated the solution Reference for the same. Also pasted to current Sitecore Instance ' bin folder C:\i...