I tried out your updated version, as I had used Glen's original in the past. There is definitely a speed boost with this version. My "test" import file is the 25 X 25 grid attached (625 BasicNode and 1200 Path Objects.) On my old laptop this imports in about 60 seconds.
I noticed that the progress bar works great for the Objects sheet, however it does not appear to update when the Links are imported. The progress remains at 0 while the links are imported, though the routine works and I see the dialogue at the end with no errors. The nodes only take about 10 seconds to import and the links constitute the remaining ~ 50 seconds. I tried turning off visibility of the links/arrows, but this made no difference. I haven’t tried vertices yet.
Also, note that I had to re-build the add-in in Visual Studio, as I seem to have an issue with adding add-in .dll's from an outside source to my ..\SimioUserExtensions directory. Hopefully I did not break the application in the process.
Thank you very much - this is very useful!
25 X 25 Grid Import.xlsx