Windows is going to show the icon of whatever program is currently set to open files of that type. What is happening is, you haven't set VEGAS 18 to be the default app that opens .veg files, so Windows is still using 17 to open those files, which is going to cause issues because 17 can't open a project built in 18. To fix this, right click on a .veg file, select properties, then next to "opens with", click "change". Set this to VEGAS 18. This should solve your problem.

Edit: I see Eric also mentioned another method that also works.

@Debbie-Whitmer It's Windows not Vegas that is showing the incorrect version. Your file is saving correctly but Windows doesn't know of the change. Go into Windows Control Panel and Default Programs where you can associate .veg with VP18.

Also your VP17 projects should open in VP18, other than any OFX that don't work in 18. But once you save it with VP18 the project won't open, or open incorrectly, in 17.

Until you alter the file association suggest you open VP18 and then open your required file from there, rather than double click on a veg file.

@EricLNZ - I so appreciate you answering! Thank you so much Eric. I did do what you said and I do understand about file association. I guess since both Vegas Pro 17 and Vegas Pro 18 have the same file extension of .veg as their file format, Windows is only going to allow me either 17 or 18 as my default program associated with .veg. I had to change it back to Vegas Pro 17 as everything works in VP17 but not in VP18.

As I had mentioned about plugins earlier in my original post, all my plugins work in VP17 but not in VP18. I notified NewBlueFX of an issue with the ZOOM plugin that comes with Transitions 3 Ultimate (I use this plugin all the time on many projects) whereas it will not allow you to pull down and drag the ZOOM icon from the "transitions tab" onto the video on the video track because you get a "do not enter" sign with a O with a line going through it; it just doesn't work but it should work. They were not aware of this problem and said they were going to report it. There is another way of being able to obtain the ZOOM plugin by fading in the beginning of the video on the video track and then right-clicking on the faded area and choosing from the menu "transition>insert other> and then choosing the ZOOM plugin from there. It is a longer work-around. There are just other plugins that just do not work at all by dragging them down onto the video tracks. Hopefully, they will come up with an update soon.

Thank you again for your help Eric. I really appreciate it very much!

Windows is going to show the icon of whatever program is currently set to open files of that type. What is happening is, you haven't set VEGAS 18 to be the default app that opens .veg files, so Windows is still using 17 to open those files, which is going to cause issues because 17 can't open a project built in 18. To fix this, right click on a .veg file, select properties, then next to "opens with", click "change". Set this to VEGAS 18. This should solve your problem.

Edit: I see Eric also mentioned another method that also works.

@fr0sty - Thank you so much for responding! Yes, I was just finding this out. But thank you for the alternative way to do this as well. You have been very kind and helpful. Thank you again!

Windows was doing the same with me too.

But it would be very useful if you could see if the template was created in VP 17 or VP18. Now this must be done by means of the name of the template such as VP18 vacation 2020

Just for my own ease of use, I've always had a folder named something like 'VEG files - Vegas Pro [version number]' along with sub-folders for all the projects that have been edited using that VP version. So for VP18, I created a new folder named 'VEG files - Vegas Pro 18' and any projects that use VP18 have their own sub-folder. If using VP18 for a project created in VP17, I create a new sub-folder with the last VP17 veg file copied into the VP18 folder. Of course, when saving for the first time in VP18 a dialogue box pops up warning that the new veg save won't be accessible in earlier versions of VP. But this way, the last saved VP17 project veg file is still in the 'VEG files - Vegas Pro 17' folder - just in case.

Re default apps in W10, changing the default as described by EricNZ and fr0sty really needs to be done with many programs when a new version is installed; for example, Sound Forge Pro, SpectraLayers Pro, PaintShop Pro, and so on - but not so much with those where a new install overrides and replaces the previous version.

Appreciate this question and answers - solved the problem for me too!