So, I am using Cubase 15 Pro and SpectraLayers 13 and when I select an audio event, go to ‘Audio’ → ‘Add Extension’ and select SpectraLayers, it opens in the editor with a blank box where the visualisation should and the text “No Data”.
I then tried opening it in the WaveLab ARA and it worked absolutely fine, no issues.
Went on to test many audio clips, all with the same resuting “No Data” message. Tried multiple ways to add SpectraLayers as an ARA (on the channel, on clip, via context & main menu), no joy. DId some quick research to see if I was missing something, nothing apparent.
I am certain this is a me issue but any help would be much appreciated.
I would suggest installing SpectraLayers 13 again (I assume you have a Pro 13 license ?).
Hello Robin, I will try that now and let you know the outcome, thank you. Oh, and yes I do, the 60% off was too good to pass up 
OK, so no dice, fresh reintall - same thing
Usually this could happen when there’s mismatch between the VST3 plugin and the installed standalone version.
If the reinstall didn’t work, I would fully uninstall SpectraLayers, then go to the VST3 folder and delete any remaining SpectraLayers files and folders (look for both).
Then reinstall, and when SpectraLayers ARA is visible, if you still have troubles please click help > Support Info > Log Output and copy its content here.
Success!
Thank you Robin. After uninstalling SL13 I checked the VST3 folder and sure enough, there were still SL VST and DLL files present in the Steinberg/SpectraLayers/ folder.
I used both 10 and 11 as trials and I wonder if these were remnants of those installs?
Whatever the case - you have really helped, thanks again and I hope you have a great Day.
