The California educational testing app CAASPP disabled Hot Corners on Mac. How can we get them back again?

Question

My son installed the California educational testing app CAASPP over six months ago to take a state required test. The only thing is it disabled Hot Corners on macOS v10.15 (Catalina) and we've not been able to get them to work again after all this time. How do we get them to work again?

We don't know how the CAASPP app disabled them, whether it was with terminal commands or AppleScript.

From page 65 of this CAASPP document about the app, we think the app disabled them using the following Terminal commands (how does it do that from the app?):

defaults write com.apple.symbolichotkeys AppleSymbolicHotKeys - dict-add 79 "{enabled = 0; value = {parameters = (65535,123, 262144); type = standard; }; }"
defaults write com.apple.symbolichotkeys AppleSymbolicHotKeys - dict-add 80 "{enabled = 0; value = { parameters = (65535, 123, 393216); type = 'standard'; }; }"
defaults write com.apple.symbolichotkeys AppleSymbolicHotKeys - dict-add 81 "{enabled = 0; value = { parameters = (65535, 124, 262144); type = 'standard'; }; }"
defaults write com.apple.symbolichotkeys AppleSymbolicHotKeys - dict-add 82 "{enabled = 0; value = { parameters = (65535, 124, 393216); type = 'standard'; }; }"

And that should be able to be reversed just by changing enabled to 1. However, when we try that we get the following error:

Unexpected argument dict-add;` And it leaves it unchanged.

How can we resolve this on Catalina?

I think the Mac OS is actually ignoring the plist file ~/Library/Preferences/com.apple.symbolichotkeys now, or there's another setting somewhere... This plist altered by CAASPP looks like this.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>AppleSymbolicHotKeys</key>
    <string>-</string>
</dict>
</plist>

We changed the plist to the below (copy and pasted the same file from another catalina mac), we restarted, reset the hotkeys, but it's still not working. What should we try next?

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>AppleSymbolicHotKeys</key>
    <dict>
        <key>79</key>
        <dict>
            <key>enabled</key>
            <true/>
        </dict>
        <key>80</key>
        <dict>
            <key>enabled</key>
            <true/>
        </dict>
        <key>81</key>
        <dict>
            <key>enabled</key>
            <true/>
        </dict>
        <key>82</key>
        <dict>
            <key>enabled</key>
            <true/>
        </dict>
    </dict>
</dict>
</plist>

Basically, the system doesn’t respond to the changes in the plist file. How do we get the system to take notice of it again?

Answer 1

I'm not sure whether the dict-add command has been deprecated since Mojave - it works on that & I don't have Catalina to test.

You could just do it the 'heavy-handed' way, manually.

Go to ~/Library/Preferences/com.apple.symbolichotkeys & open it in BBEdit [freeware version is sufficient.] TextEdit will not be able to make any sense of it.

Find >79< & just below that, change the false to true.
Repeat for the other keys.

Save, then reboot.

Answer 2

dict-add is fine in Catalina, but you've got a typo. - dict-add should be -dict-add.

You're running defaults write domain key - dict-add …, which is writing - to the key for the domain. That's why the plist has <string>-</string> as the key's value after running that command.

Instead, you should use the -dict-add option which is described in the usage as:

-dict-add <key1> <value1>

Answer 3

We finally resolved this. The CAASSP software had disabled Mission Control, so any fixes to the plist file ~/Library/Preferences/com.apple.symbolichotkeys were not working as I'm assuming that file was being ignored as it's read by Mission Control? Anyway, it was not working.

However, with a combination of @Tetsujin's fix above, and also enabling Mission Control, we now have Hot Corners working again.

Here's a stack exchange link on how to enable Mission Control. https://apple.stackexchange.com/questions/170488/osx-yosemite-mission-control-stopped-working

Yay Hot Corners!