After I boot up my PC in the morning I can open the Dorico application without any problem. If I work on a flow and subsequently close the program, I’m unable to reopen the application - nothing happens. I have to restart the computer in order to get the application to open.
I don’t have this problem with any other software applications on my PC so I have to assume that the problem is, somehow, with Dorico.
Would appreciate help/advice
Dorico and its audio engine run as two different processes: Dorico and VST Audio Engine. If you’re forcibly closing Dorico (via Task Manager on Windows or Activity Monitor on MacOS) you need to also forcibly close VST Audio Engine.
Without further information we can’t know exactly what it is that’s preventing Dorico from closing normally, but force quitting VST Audio Engine will allow Dorico to be launched again without rebooting the whole computer.
I’ve been closing the program by selecting “Exit”, not using the Task Manager.
When I access Task Manager, after I’ve selected “Exit” for Dorico, neither Dorico nor the VST Audio engine appear.
The VSTAudioEngine is a headless background process and Task Manager may not list it properly. There is a better tool, the free app called Process Explorer which you can download from here. Have a look at the end of the list for either Dorico or VSTAudioEngine and do a right click on a process to kill it (choose from the pop-up menu).
I’ve had exactly the same experience - after using Dorico 4 for a while, close the app (not force quit, just a normal app exit), and then it refuses to re-launch (No splash screen).
In my case, I had to forcibly kill SteinbergLicenseManager.exe (VSTAudioEngine5.exe was in the background too, but that wasn’t stopping Dorico from launching).
It’s work-around-able, but the app does seem to have issues tidying up after itself.
Hi @Ulf - yes, I’m on Dorico Elements 4
Version 4.3.30.1132 (Mar 10 2023)
Dorico 4 AudioEngine Version 5.5.0.67
(Windows 11)
I should add though - just to make things more difficult to diagnose 
- this isn’t 100% percent repeatable. I’ve been opening and closing Dorico a number of times this morning without any issues.
I’ll try to see if there’s any pattern (such as leaving Dorico open while putting the machine to sleep) and report more if I can find something repeatable.
You should ideally wait for around 10 seconds after quitting Dorico before starting it again, to make sure that the audio engine has had a chance to exit.
And what if you open 2 projects at the same time, does that work?