@Antoine
I didn’t heed my own usual advice and installed the latest update this morning 2.9.4. Noticed straight away that the ability to add in Plug Ins had disappeared as follows:
So went back to 2.9.3 and got this classic:
Any ideas on:
Would try removing and reinstalling 2.9.4. The processing section is present on my installation of 2.9.4 and plugins can be set.
@Djm1960 Yes I restarted the Macbook Air. Did another re-install and it is working, however I have no Processing Section so no plugins unfortunately.
Are you on Mac or other??
It’s working just fine for me (macOS Sequoia 15.1) Audirvana Studio 2.9.4…
Screenshot while playing a 24/352.8kHz AIFF file:
I have the same issue with no plugin management in the pipeline… The debug does show that the two plugins I use are there… I also experience a thermal issue which most likely means heave load on the cpu…
Working fine on 15.1 for me. Try removing your database file to a backup location and delete the one on your internal SSD. Restart AS and it will create a new DB file to see if that resolves the issue….
Are you playing FLAC files as is @ChiliHot?
@Agoldnear Flac with upsample to DSD128
Yep, I saw that… I’m wondering if @Ddude003 is playing FLAC files…
MacOS:
That would be great, if we could actually get Real Time Proocessing.
I’m still on Sonoma 14.7. May be time to do upgrade to 15.1.
I’m going to reinstall one more time to see if it brings the processing back??
Yes… of course… 
For info, turned on a plugin and upsampling to DSD and playing a FLAC file on 2.9.4 is fine for me (and surprisingly pleasing, don’t normally upsample to DSD but maybe worth an extended trial!)
My first impression of the sound-quality of Audirvana 2.9.4 on my set-up and configuration, is having an incremental improvement in contextual detail and focus! 
I have no baseline for upsampling to DSD so can’t comment other than to say I increased the DSD rate to 128 (the max on the LS50’s in my office) and played my reference tracks……… maybe I am not a PCM guy after all, sound quality was sublime. An extended trial is definitely warranted……
@Antoine Have updated Mac to 15.1. Reinstalled Audirvana again, however still not getting the Processing Option Box for Plugins.
I did not have processing on before i did the update. Could that be the reason? If it wasn’t on before the update it gets ignored??
This is on the Debug:
SIGNAL PROCESSING:
Polarity Inversion:
Globally: OFF
Per track: ON
*Effects plugins NOT ACTIVE*
When you removed AS 2.9.4 did you remove all of the preference files as well as your database and the application? Try with a totally clean setup of 2.9.4. Just deleting the app will not remove the old preference files, maybe worth a try if you have not done so already……
Would not know where to start? Is there a guideline somewhere handy??, otherwise I will try and do a forum search at some stage. Im running out of puff, unfortunately…
I installed 2.9.4 on an installation where no plugins were used (I don’t use any). Then turned on an Apple EQ plugin and upsampled to DSD to try and replicate your issue. As previously stated it worked fine so plugins not being on when installing 2.9.4 is probably not the issue.