Possible Workaround: PSD causes "Photoshop could not complete your request because the file was not found" Error

Mac OS X 10.11.6, Photoshop CC18 19.1

I work at a printing company as the supervisor of the graphic design/pre-press department, and I encountered the "Photoshop could not complete your request because the file was not found" error when trying to open two Photoshop files that were sent to us (first via Dropbox, then via Google Drive, for the record). Finder would preview them with no problem, but Photoshop would only give the mentioned error when attempting to open them, whether by double-clicking on them, right-clicking and "Opening With" or opening via the Photoshop Open menu. My two coworkers in the department, who each have their own individual Adobe IDs and Creative Cloud installations on two separate, but otherwise identical computers, encountered the same problem, but neither the client nor their designer had any issues opening the files (they're both using Creative Cloud as well).

I contacted Adobe Customer Support, and the following steps were taken.

1. Delete all Photoshop preferences and settings and try to open the files (fail)
2. Check that the most current version of Adobe Camera Raw support is installed (it is)
3. Open a different, unrelated file with Photoshop (success)
4. Transfer files to ACS agent and have him attempt to open files on his computer (success)
5. Have ACS agent send a new file back to me, and attempt to open it on my computer (fail)
6. Create a new user account on my computer and open the files with Photoshop in that account (success)

These results led Adobe Customer Support to offer the solution of creating a new user account and having Apple support help me port over my current one, because something in the current account’s (as well as in the separate accounts on my co-worker's computers) settings or permissions has corrupted, resulting in the file not being allowed to be opened. If you work in an office setting, you'll recognize the unpalatability of this solution, and hopefully understand my aversion to doing so.

As such, before contacting Apple support, I reached out to our contracted IT company, because that's what we pay them for. After several false starts (including running First Aid, and using the Creative Cloud cleaner and doing a hard reinstall), IT and I discovered two things:

1. even though Photoshop was refusing to open the file, Illustrator (CC18 22.0.1) was able to do so, and more importantly
2. the files were saved in sRGB IEC61966-2.1 colorspace, but our internal working color profile uses the Adobe RGB (1998) colorspace for RGB files (before you say anything, yes, we convert 'em all over to CMYK in the end). Switching Photoshop over to sRGB prior to opening the file resulted in Photoshop having no trouble opening the file, which I was then able to save to the desktop, reassign the color profile to Adobe RGB, and then close, reopen, edit, and generally work with without further error.

I am writing this post for two reasons—I want this information to be available to anyone else encountering this issue, to help avoid the potential "solution" of moving all their data to a new user account and deleting the old one.

I also want to say that while the gentlemen who I talked to at Adobe Customer Support were as helpful as they could be, the fact that simply manually setting the colorspace before opening the file is nowhere on a troubleshooting list that ends with "nuking your old user account and starting a new one" is a little bit baffling. When I spoke to them about the workaround I had found, they argued that it wasn't a solution to the problem, and I completely agree with them. However, it's just as "good" of a solution as the alternative, and frankly, a whole lot quicker.

–JG