Is there a any way to generate css file from less file ? As we have some less files in project solution but doesn't seems to be changing while save or compile. Let us know if need to install any tool or vsix in visual studio?
This is the documentation for Zero v4.0.
Bundling, Minifying and Compiling
ASP.NET Zero uses Bundler & Minifier Visual Studio extension(https://visualstudiogallery.msdn.microsoft.com/9ec27da7-e24b-4d56-8064-fd7e88ac1c40) for bundling & minifying script and style files. It should be installed in your Visual Studio. bundleconfig.json file defines all bundling configuration.
ASP.NET Zero also uses Web Compiler Visual Studio extension(https://marketplace.visualstudio.com/items?itemName=MadsKristensen.WebCompiler) for compiling LESS files to CSS files. This extension also should be installed in your Visual Studio. compilerconfig.json defines all compiling configuration.
See documentation of these extensions to learn to use them.