Imported Geometry Issues

I'm having issues with the imported geometry tool in Solidworks 2018.  I used to be able to start a new part and then import a single IGES file with multiple parts in it, but now am unable to.  When I attempt to use the imported geometry tool nothing will open or show.  In addition, I can open a single IGES part one at a time, but when i go to open/import a second single IGES part into the same part file it will replace the previous imported file.  Anyone running into similar issues or have a solution to this?