Photoshop blocked each time I try to use it

check to verify your >System Preferences / Security & Privacy [General]

is set to Allow apps downloaded from:

App Store and identified developers

Your system looks clean and I found nothing I'd conclusively say is causing problems so here's some questions

Are you running legacy Adobe products from that system?

Did you do a clean install of CC from the desktop manager and use the most recent version to re-download the packages you need?

Release notes for the Adobe Creative Cloud desktop app

or did you migrate it over from a backup, a clone, an image or something else?

As of yesterday I deployed an iMac Pro to a user who told me PS CC2018 was "acting strange" but I have not had a chance to see what he was talking about and I'm pretty sure it was not the developer identifier. I had another user whos behavior in PS CC2018 was bonkers and I had to do an SMC reset to fix it, but it was because it was slow (you can try this, it wont hurt), but not that it was throwing an error about being blocked.

How to reset the System Management Controller (SMC) on your Mac - Apple Support

on that note it could be the developer identifier is missing (legacy versions of Adobe product), corrupt or compromised (sometimes copying the installer file does this) or the gatekeeper, or your account is whack. In the latter I would create a new admin account, boot to that account and see if the problem is resolved, if not I would uninstall your adobe suite and clean install the whole thing. My advice is far from the only advice here so you may want to ask around.

Select any jpg in the Finder. Press "command + i". In the Get Info window that opens change "Open with:" to whatever you want the default app to be, Photoshop etc. Then press the "Change All…" button. Close the Get Info window.

Try double clicking on a jpg.

See this article macOS Sierra: Open an app from an unidentified developer

Note: You can also grant an exception for a blocked app by clicking the “Open Anyway” button in the General pane of Security & Privacy preferences. This button is available for about an hour after you try to open the app.

To open this pane, choose Apple menu > System Preferences, click Security & Privacy, then click General.

Just clarifying it has nothing to do with Photoshop. Something is wrong with your system.

Please install EtreCheck and post the report.

http://etrecheck.com/

There is no question that you should feel compelled to use software you are unfamiliar with; but in this case you can check these forums to see how frequently this tool is used to diagnose system issues. The developer is an active contributor to these forums.

Etrecheck is a invaluable package used here in so many instance I could not count, and it does not provide anyone with any personal information. I suggest you continue to inquire with others here regarding this software if you have any concerns.

The fact he is not the greatest web designer should be a concern if you hired him to build you a web page. 🙂

You have not just one, but two remote access software packages running on your Mac. TeamViewer and Bomgar. Get rid of them.

I can't see any reason for Caphyon to exist as it seems to be a Windows app installing tool.

Do you really need all of these Safari extensions? All of Google's apps are extreme resource hogs. On your system that would be Chrome and Google Earth. Get rid of at least Google Earth. Remove any other unnecessary extensions, such as Silverlight and ShockWave, which virtually no one uses anymore.

The ProTec6 anti-piracy app is a known problem. It causes Macs to run slow, and just generally run badly. It appears it's installed as part of Nik filters, Portrait Pro, and probably other vendors who use it.

Edit: Forgot this part.

xxxx.jpg can't be opened because it is from an unidentified developer

That's not an an OS message about Photoshop. The OS is, for whatever reason, saying a .jpg can't be opened because it's from an unidentified developer, as if it were an app rather than a file.

Apps downloaded from internet are treated as third party apps they can or can not be compatible with Mac , even apps from App Store are outsourced , you can consult apple support for this ( if the app is not opening means it is not compatible ) after all it's up to you .

Read this article About System Integrity Protection on your Mac - Apple Support

FWIW, The error message doesn't say Photoshop can't be opened.

Have you tried opening Photoshop without opening a file?

Kurt Lang wrote:

Edit: Forgot this part.

xxxx.jpg can't be opened because it is from an unidentified developer

That's not an an OS message about Photoshop. The OS is, for whatever reason, saying a .jpg can't be opened because it's from an unidentified developer, as if it were an app rather than a file.

Indeed. Is what I was thinking.

FWIW, The error message doesn't say Photoshop can't be opened.

Colin,

Due to the settings you chose in security, you won't be able to download this app via the source you acquired it from- that's the bottom line.

You can either disable that setting and put your computer at risk, or find a secure, credible download that your system feels is credible and safe for download