It looks like that message gets shown to your based on the settings at "Settings > Transition Settings > Full Scan".
In order to export an isolation list for a Sciex TOF instrument, the "Acquisition Method" needs to be "DIA" and the isolation scheme has to be something where you have explicitly listed the isolation windows. That is, in the "Edit Isolation Scheme" dialog, there has to be a list of prespecified isolation windows; the radio button "Use results data isolation targets" cannot be checked.

I certainly understand why it would not make sense to export an isolation list if the isolation scheme was "results only", since Skyline would not know what the isolation windows were supposed to be.

However, I would expect things to work if you had specified "PRM" as the Acquisition Method at "Settings > Transition Settings > Full Scan". It seems to me that it is a bug that Skyline insists that the Acquisition Method be "DIA" for Sciex TOF.

Which Acquisition Method do you have specified at "Settings > Transition Settings > Full Scan"?

If you send us your Skyline document, it might help us figure out whether there is a bug here that we should fix.
In Skyline you can use the menu item:
File > Share
to create a .zip file containing your Skyline document and supporting files.

If that .zip file is less than 50MB you can attach it to this support request. You can upload larger files here:
https://skyline.ms/files.url
-- Nick