I had the same issue a few minutes ago, but now resolved. PSO2 needs Visual C++ Redistributable for Visual Studio 2015 file to run the software correctly. Downloading msvcp140.dll file and manually placing it into the folder will not work.
The software relies on several files, so you are better off installing the files using the official link from Microsoft website. Here's the link https://www.microsoft.com/en-us/download/details.aspx?id=48145