This has been an issue that I've experienced for well over a year now and was reported to have been fixed with version 23.0.1, but I updated to that version several months ago and am still to this day experiencing this issue. If you don't already have Illustrator open and launch the program by double-clicking an AI file (or choosing "Edit in Adobe Illustrator" when right-clicking on a link in InDesign), the document in question does not appear to be open and additional attempts to open said file result in either nothing or a dialog box telling you the file is already open. The document can ONLY be viewed by choosing "Float in Window" from the Window menu, which is highly annoying and inefficient. Perhaps this bug was solved in the Windows version of Illustrator, but it is very much alive in the Mac version, as it literally just happened to me minutes ago. Please solve this extremely aggravating error!