Extremely slow startup of Dorico audio engine

Starting up the audio enginne for Dorico takes 4-5 mintes for me on a current and very powerful computer.

I have a lot of VSTs installed. Could this be the reason? Are there other possible causes to look for?

The first time you start a new version of Dorico, or the first time you start up after having reset your preferences or cleared the audio engine cache, it will take a while because it will be scanning your plug-ins. Subsequent runs should be faster, though if you have a really excessive number of plug-ins even enumerating them might take a while. If you’d like us to investigate, please do Help > Create Diagnostic Report and attach the resulting zip file here.

I have a lot of plug-ins, and after a few seconds from launching it Dorico asks if I want to wait or terminate. If I wait, and repeat the same answer at the subsequent request, the boot completes regularly.

This behavior didn’t happen with the previous version.

Maybe the expected wait could be longer, with a message warning that Dorico is scanning the plug-ins, and asking to be patient.


Hi @Paolo_T , is every start up so slow? Could you also please post a diagnostics report? Thanks

No, some are, some not. I can’t understand when this happens. Something that I’ve noticed:

  • It happens when Vienna Ensemble Pro is ready and idle, and you open a Dorico project making use of it.

  • It happens when running Dorico the first time in a day.

Please find the diagnostic generate by terminating the launch of Dorico.


Dorico Diagnostics.zip (1.0 MB)

Hm, in the logs I sometimes see big jumps in time during the plug-in scanning, but don’t know what your computer is doing then.
You have quite a number of VST2 plugs. In order to get closer to the problem, I propose to temporarily hide all the VST2 plugs from Dorico and then see how it starts up.
Therefore please rename the folders /Library/Audio/Plug-ins/VST and /LibraryAudio/Plug-ins/VST2 (yes, these paths are in the root of your harddisk, not your home directory) to something else. If you then start up Dorico a couple of times, how does it behave then? Thanks

Done. I’ve tried relaunching Dorico various times, and it was very fast.

But then I restore the original names to the VST/2 folders, and there was no difference.

I’ll try again in the same way, should the issue reappear.


Hi Paolo, to be honest, I did not expect this result. Well, yes, after the first renaming, okay, but why now after renaming to the original name everything seems to be fine…? Well, then let things as they are, and come back should you have trouble again.

Here we are again. This time I was launching Dorico, after having loaded something in VEP.

I had tried opening Dorico with a blank VEP instance earlier, and everything went fine.

The VST folders in the Library have the original names.

Launching Dorico a second time works perfectly fine.


Dorico Diagnostics 2023-12-21.zip (928.6 KB)

Hi @Paolo_T , please read my private message I’ve sent you.

Hi @Ulf,

This time I didn’t open VEP. Just launching Dorico caused it to wait, and then asking me if I wanted to terminate it, because there was no connection with the audio engine.

This happened the first time I launched it in the day. No Mac restart had happened. When I launched Dorico again, after terminating it, it launched fast, with no error message.


Dorico Diagnostics 2023-12-22.zip (957.0 KB)

Hi @Paolo_T , let’s have a remote session in the new year.