I'll start by saying that I'm on an iMac with High Sierra and using Adobe CC 2018. When I export an image from Illustrator and then double click the exported image, it defaults to opening with Preview. I'll then right click and use "open with", then select Photoshop as the app and "always open with", however, when I then double click the image, it gives me the same message you'd receive from an app that is from an unidentified developer, but this is a JPEG image. I'll then click "open anyway" and it opens in Photoshop, but anytime I export any new image from Illustrator, it treats it like another new app from an unidentified developer. It does this for literally any image I export so I have to drag the image to the PS icon or open within Photoshop to open images. I've never had this problem before updating to High Sierra.
Is there a way to get my mac to no longer treat any and all images I export as being from an unidentified developer? I asked this same question in the Apple Communities with no answers, so I'm hoping someone here might have some insight should it be Adobe-related.
I do not get the message when I open a file from within Photoshop; I only get the message when I right click the image file and select "open with-->other" and choose Photoshop, then "always open with", and finally "open anyway" after it tells me it's from an unidentified developer. Once I've done this, the image will always open with a double click, but it only applies to that image. Any other image I export from Illustrator (or download from the internet for that matter) will require the same process again to get it to open with a double click. Quitting or not quitting Photoshop does not effect anything.