It is generally accepted that only ONE instance should ever be opened.
Testing some time ago worked Ok for the most part but could on occasion result in the loss of one of the sketches.
For multiple instances of the IDE it is often better to use the desktop versions.
Your topic was moved to its current location as it is more suitable.
Could you also take a few moments to Learn How To Use The Forum.
It will help you get the best out of the forum in the future.
Thank you