I can't (;-)) maybe Marco can? I thought that maybe this was a conflict with windows 11, but you have this with windows 10, so it's a PL/SQL Developer issue. This issue is mostly annoying at the start of the day, when I start up all my applications in use. I "navigate" to the PL/SQL Developer button which then starts a new instance of PL/SQL Developer so I end up with 2 instances(or 3 etc. if I have not noticed that there are already instances running). I already explained several times why this issue is a problem in several threads. Would be nice if this issue got fixed.