Error when attempting to install Zotero for Mac

sjjohnson23

When I download the .dmg for Mac and double click or ctrl-click, whether from the downloads folder or after dragging to the applications menu, I get the following message:

"Zotero-5.0.96.2.dmg" is damaged and can't be opened. You should move it to the trash.

I'm running an olddd version of iOS, Mojave 10.14.6. I'd prefer not to update, so if there are any things I can try before then, I would super appreciate it!

Thanks!

sjjohnson23

Update of sorts:
I also tried Zotero 4.0; no dice.

dstillman

It sounds like your downloads are being corrupted somehow. The .dmg on the site is certainly fine.

Try downloading 5.0 using a different browser, or if that doesn't help, from a different network.

Don't use 4.0. 5.0 should run fine on Mojave.

sjjohnson23

Thanks for responding!

I tried it (originally) on Chrome, and again on Safari on your suggestion. Still nothing there.

I have downloaded it from eduroam (ostensibly decent university blanket network), a visitor network (maybe same tubes), and finally using my phone as a hotspot; once each on Safari and Chrome.

Beginning to suspect there's some security setting deep in the bowels of this laptop I need to fiddle with.

dstillman

There are no built-in security settings that should prevent opening a properly signed .dmg, but there could be something broken. I'm afraid your best bet really would be upgrading from Mojave.

But just to poke around slightly, if you open Terminal via Spotlight, type md5sum (with a space at the end), drag in the .dmg to paste the path, and then press Return, what does it show?

If you type hdiutil attach (again with a space at the end) and then drag in the .dmg and press Return, what does that show?

sjjohnson23

Problem solved! You were correct, it was definitely not the .dmg itself.

md5sum didn't do anything, unfortunately.

I did the hdiutil attach, and it opened the .dmg and plopped it into my app folder, but I was still getting the same error.

I poked around in my security settings, and Apple has oh so protectively disabled my ability to install anything not from their app store. Switched that setting to find out that it kept switching back to the restricting one, and nearly lost my academic aplomb.

FINALLY, my partner had me brute-force it w/ sudo spctl --master-disable and... LO AND BEHOLD, I got me some sweet sweet Zotero action on this 9-year-old MBAir!

It's not the *worst* way I've avoided actually working on my research, but any excuse will do.

THANK YOU, dstillman! I very much appreciate your help in getting me where all problems with Apple OS go to die: Terminal.

dstillman

md5sum wasn't supposed to fix anything — it just outputs a fingerprint of the file that can be used to verify that it wasn't corrupted or modified during the download. While that almost certainly wasn't the problem here, you technically did just install a program that was failing security checks without verifying that you had the original file from our servers.

sudo spctl --master-disable

This completely disables Gatekeeper — checking of downloaded files for code signatures — and I would strongly encourage you to turn that back on. You should certainly be able to change the App-Store-only setting, and if you can't, fixing that would be the thing to do, not disabling Gatekeeper.

sjjohnson23

Ah, sorry I wasn't clear. md5sum didn't do anything at all. I got "command not found" when I ran it. Went back after I got Zotero on and used plain ol' md5 (minus "sum") and got the checksum to run. Now that it's moot, I compared it against another installation on another machine and hey presto, it's not corrupted or damaged, so yay?

Disabling Gatekeeper was the nuclear option, yes, but once Zotero got in, I put in an exception in GK for Zotero and turned it back on, then confirmed that GK was still being as sulkily unwelcoming as before.

No idea what the Magically Resetting app-store-only setting problem is, but since I can't find anyone having posted or reported the same issue yet, I'm reasonably happy with how it turned out until I can solve that problem.