Turn off Windows Defender real-time protection. Add the entire C:\EC-Apps folder (where ISTA lives) as an exclusion.
Here are some tips and tricks to help you get the most out of BMW ISTA: Bmw Ista - Download
For genuine, up-to-date software, you can download ISTA directly from the BMW AOS (Aftersales Online System) Turn off Windows Defender real-time protection
Before downloading anything, you must understand that "ISTA" is an umbrella term. There are two primary versions you will encounter: Bmw Ista - Download