Exploring the Sitecore

https://docs.mongodb.com/master/tutorial/install-mongodb-on-windows/

I just had the same problem. Visual Studio isn't building the project that's being referenced. Right click on the solution and click Properties. Click Configuration Properties -> Configuration on the left. Make sure the check box under "Build" for the project it can't find is checked. If it is already checked, uncheck, hit apply and check the boxes again. https://stackoverflow.com/questions/1421862/metadata-file-dll-could-not-be-found

http://www.sqlideas.com/2011/08/split-database-full-backup-to-mupltiple.html

https://www.akshaysura.com/2017/09/07/sitecore-multi-site-custom-500-error-page/

http://sitecoresolution.blogspot.in/2017/04/setting-up-sitecore-helix-solution-from-scratch.html

https://www.youtube.com/watch?v=cskz2oZYCYs