@Luis_Martinez: I had a nearly similar issue with mspdb120.dll when I had both VS2010Pro, VS2013EE, some WinSDKs installed. I had to uninstall them all, which was a bit tricky, had to check installation dates to remove everything, then installed VS2013Community and it have been fixed. The same >might be< the reason, but not for sure.
the old thread: https://answers.unrealengine.com/questions/54957/converting-project-to-42-missing-dll-error.htmlEdit: if that dll is missing probably you have not installed VC++ redistributables, and most importantly you need VS2015 for UE4.10 (you mentioned to have only VS2013)