Hi John,
Sorry, my post was a bit short on info......
My computer is a win10 PC.
I think I found where to "play" with the protection, but have no clue what boxes to check......
DaveL
If you are running Windows Defender:
Go into settings - the Gear icon on the Windows menu or under the Actions menu located on the far right near the clock.
Click on Update & Security
On the right, click on Open Windows Security.
Click on Virus & threat protection
On the right panel, click Manage settings located under Virus & threat protection settings
Scroll down until you see Exclusions.
Click on Add or remove exclusions
A security box will come up. Click on Yes.
Click on + Add an exclusion.
Click on Folder.
A Windows Explorer window will open up...
Browse for your Trainz program.
Add in C:\Program Files\N3V Games\ and then the Trainz version you have installed. (I have Trainz Plus) so I selected that one. (If you installed it on another driver, browse to that one instead).
Repeat the + Add an exclusion and add in your Trainz data-folder wherever that is by browsing for it in the same way and selecting that one.
Once done close the windows since you don't need to do this any longer.