The macOS dictionary app cannot add new build in dictionaries

Yes it works. A, the file name has to be changed to another name like Portuguese - English2.dictionary, with a "2" added here. B, reopen the dictionary and preference, scroll down to the bottom of the list. Check the newly added dictionary.

A bit more information, but unfortunately no solution...

The system dictionaries seem to be stored here:

/System/Library/AssetsV2/com_apple_MobileAsset_DictionaryServices_dictionaryOSX

This is in the System folder, so to actually manipulate anything here, one has to disable System Integrity Protection (proceed with caution).

If one deletes any of those asset folders, Dictionary.app recreates it when we select the dictionary again.

Now, in that folder, there is also the following file:

com_apple_MobileAsset_DictionaryServices_dictionaryOSX.xml

which has the link to all dictionaries on Apple's servers. For instance, for the Portuguese-English dictionary:

<key>__BaseURL</key>
			<string>http://appldnld.apple.com/ios11.0/048-04169-20171219-3E638938-E064-11E7-BED0-328EE988D09B/</string>
<key>__CanUseLocalCacheServer</key>
<true/>
<key>__InstallWithOS</key>
<true/>
<key>__RelativePath</key>
			<string>com_apple_MobileAsset_DictionaryServices_dictionaryOSX/163595ab3e757c8ac7fa284e89f101919e3ad920.zip</string>

meaning one can get the dictionary from:

http://appldnld.apple.com/ios11.0/048-04169-20171219-3E638938-E064-11E7-BED0-328EE988D09B/com_apple_MobileAsset_DictionaryServices_dictionaryOSX/163595ab3e757c8ac7fa284e89f101919e3ad920.zip

I copied this file into the said folder, gave it the adequate permissions and tried seeing if Dictionary.app would see them. It didn't work because as soon as I selected these files on the preferences, they were deleted from the folder.

Ran out of ideas, so I give up...

Following scheeko's discovery, I figured out that you don't actually have to download anything. All the dictionaries are already preinstalled, located at

/System/Library/AssetsV2/PreinstalledAssetsV2/InstallWithOs/com_apple_MobileAsset_DictionaryServices_dictionaryOSX

Some of the dictionaries here are actually newer than the ones found in the download links in that xml file.

After moving to a new MBP 16" (10.15.1) from a MBP 15"(10.14.6), I'm seeing the exact same issue.

I tried the following:

• Create new user
• Reinstall MacOS

Neither worked and I saw the same problems after both cases.

I also ran into this issue with the new 16in MBP (10.15.1) and the Dictionary app when trying to add the Oxford Portuguese-English dictionary (2015, 2019).

As others have described, the checkmark flashes on, then off and the dictionary appears to be added to the Nav bar, but once you close the Preferences window, it disappears.

Correct, they guide though basic steps, including MacOS reinstall. However, if it doesn't resolve the issue, they still work on the case. The next step is to schedule a call with your local phone support engineer, do remote session, get screen capture, collect the logs and file a case with engineering and then do regular follow ups. At least it works like this in US.

Not sure I did it right as I’m not 100% sure what you mean by /Users/<user> but it did not work. Here is what I did, please correct me where I went wrong.

Finder/Home Folder/Menu Bar> Click Go> Hold down option key> Library appears> Click Library> Dictionaries>CoreDataUbiquitySupport folder removed to trash.

closed Finder > opened Dictionary>Clicked on preferred languages> closed Dictionary

but the languages do not go into dictionary. Right clicking or highlighting a word brings up a window that reads...

No Local Dictionary Available

configure dictionaries

if I click on that and try to sent languages nothing happens.

Same. It's surely an issue of macOS catalina. My 15 inch macbook pro with 10.14 doesn't have such an issue, while the new 16 inch with either 10.15 or 10.15.1 has a broken dictionary.

Also remember to restart your computer! In my case the Look Up didn't show the dictionary I selected before I restarted my computer.

You do not need that file. You only need to to remove all things in folder

/Users/<user>/Library/Dictionaries

After that open Dictionary app and choose which dictionary you want to use.

I met the same problem as Hahaha66. Besides his problem, I also found that I cannot search any word in dictionary. Although I checked some of the dictionaries, no matter what word I tried to look up for, it tells me “entry not found”. I tried restart my device or create another test account, but still failed to solve this problem. Is there a way to fix it without reinstall macOS?

Actually, I tried one more thing and it works, as a temporary solution.

1. Download the from the links in the

com_apple_MobileAsset_DictionaryServices_dictionaryOSX.xml

file, as exemplified in my comment above.

2. Instead of going to the system folder, add to your user's Dictionary folder:

/Users/<user>/Library/Dictionaries

3. Rename the file to a different name, eg.

Portuguese - English2.dictionary

4. Voilá: a duplicate entrance will show up on the preferences and this one is now selectable and usable.

Hello scheeko:

Thank you for your reply. I tried the previous solution, but it did not work for me. I am not sure if I did it wrong.

I first got the 163595ab3e757c8ac7fa284e89f101919e3ad920 file from the link.

Then I put the whole folder under the path

/Users/<users>/Library/Dictionaries 

Then I went to

/Users/<users>/Library/Dictionaries/163595ab3e757c8ac7fa284e89f101919e3ad920/AssetData 

I changed the dictionary file from Portuguese - English.dictionary to Portuguese - English2.dictionary

However, the new entrance did not appear on my dictionary preference.

I am not sure where I did wrong. Could you help me with that？ Thank you!

Thanks all the guys, I finally fix the problem, by the way, there is a tip for newbie (as I am), if you can't find /Library/ folder in your <user> folder, just open finder, and press option button then click go to, the library will show up.

Thanks at all

Thank you for pointing out the problem. I also have this problem with my 16" Macbook pro on the brand new build that came with the computer. As of February 2020, no fix has been provided by Apple. I hope this issue gets the attention it deserves.