Hi everyone,

I got a very useful piece of advice from technical support:

Get["EntityFramework`"]

apparently fixes (some of?) the problem at least for the active session. If you restart Mathematica then you will need to run that again. I gather that this is not the final solution, but we are definitely getting there.

I would be grateful if other people with that problem could try this and report back whether it worked for them. It worked on all computers I currently have access to.

The technical support was extremely friendly and helpful. A very good service indeed.

Cheers,

Marco

Dear Hans,

thanks a lot for checking. I am getting frustrated that Voodoo does not seem to apply to me. Is it included in Premier Service Plus?

Cheers,

M.

Works for me as well now in both Fedora Linux systems with Mathematica 10.1 and Windows 7 with Wolfram Desktop 10.1. I can see the initialization of the Wolfram Knowledgebase connection after loading the EntityFramework and running EnityValue again

Mathematica 10 comes with, and should use, its own installation of Java (specifically a Java 7, I believe at $InstallationDirectory/SystemFiles/Java). There should be no need to install Java yourself, even on Mac.

I'm suspicious of the space character in the $InstallationDirectory of /Applications/Mathematica 2.app/Contents for the non-working system quoted by Marco above. I could easily be wrong, but try using a different installation directory that does not include a space?

A suggestion from tech support:

execute

RebuildPacletData[]

Considering the lack of paclet files in your printout of SystemInformation[], it might do something.

I got an e-mail from Wolfram Support, and suggested that I un-install Java. As I discovered when doing this, The Java 8 installer (for the Mac, at least) just installs a plug-in. It does not install the JDK, as, apparently, it used to.

The strange thing is that once I uninstalled Java 8, Mathematica 10.1 still evaluated EntityValue[] correctly. As the tech support person pointed out, how Mathematica works should not be influenced by what is essentially a browser plug-in.

Kenneth's observation is correct: when the function was not working, the blue box indicating that the WolframKnowledgebase connection was being initialized did not appear. Now, it does.

So, what I am left with is a working Mathematica 10.1 after some voodoo that was a side effect of installing Java 8 on OS X. Now that it works, the presence or absence of the plug-in makes no difference.

Completely resetting Mathematica 10.1 (deleting the base directories, re-installing from a fresh download) did not fix the problem. Whatever it did, running the Java 8 installer made the problem go away.

Since others have tried this bit of magic without success, clearly something else is going on, to state the obvious. If, as Marco discovered, CityData[] works and EntityValue[] does not, accessing the same data, the issue cannot be in the connection to the knowledge base.

I'm out of ideas. I had a magic trick that worked for me (good for me) but no idea why, or what to do to solve the problem.

Did you try deleting the BaseDirectory and UserBaseDirectory and let Mathematica re-create them? (On my system, Mathematica only rebuilt $UserBaseDirectory, but that is sufficient.)

I did that, and it didn't work, but it was right before I had the 'bright' idea of installing Java 8. It is possible that the Java bit was just a co-incidence, and the real problem was a messed up library directory. If I had restarted or something else, it may have been that the problem would have gone away.

It may be just a hunch, but if Mathematica does not put a Mathematica folder in the System Library (OS X -- other systems have different names), try not making one by hand or copying from an older/other computer. I had some issues with old cruft in the Mathematica folder in the system Library folder in the past -- which is why it is no real pain to toss it. I do know that an issue I had with the welcome screen not remembering recently opened notebooks went away when I tossed the library folders and used only what Mathematica built on its own.

Considering the lack of content in the library folders of the non-functional systems, it may be worth a shot. It would not explain the issues on Linux or Windows, but OS X after 10.8 or so has had restrictions on what goes into the system library folder, and I have noticed that a lot fewer apps put things there, and when they do, it seems to be read-only. Just a guess.

Thanks everyone for looking into this. The Java remedy does not seem to fix it for me.

I'll try to get advice from tech support, too.

Cheers,

M.

Sure. If I find anything out, I will post it here.

Thanks a lot,

Marco

I included a link to this discussion in the e-mail I sent to tech support. (If you have not sent them a missive, I suggest that you do.) Perhaps they will read this and have some suggestions.

Mine is a pretty simple set up -- no corporate firewalls, etc. and, as of yesterday, a plain vanilla installation of Mathematica 10.1. Dealing with curated data involves a lot of 'moving parts'.

If I get a response from tech support, I will post it here.

Hi,

I believe that that is the same issue. If I execute that on a "good" computer it works. If I run it on a "bad" one that does not work. Could you please run one of the commands we discussed above to check whether they work?

A couple of minutes ago I got one computer working by reinstalling Java, deleting Mathematica completely and then reinstalling it. But this does not always seem to work. I am not really sure what is going on here, but I am getting more and more convinced that George is right and it is a mere Java issue. I just do not understand why reinstalling Java and then Mathematica does not always fix the problem. There might be some remaining files on the system or something.

Cheers,

Marco

Hi,

which Java version do you use?

Cheers,

Marco

not sure who the query was addressed to, but here is what worked for me.

On a Mac, OS X will offer to install Java 6 SE if an app needs Java. This did not solve the problem with Mathematica. I went to the Java (Oracle) site (www.java.com), and downloaded Java 8 update 45, which is what was available for OS X. This solved the problem.

Note sure about Windows, but I guess that there are various versions of the Java runtime available, and the most recent is the one needed. From the Java website, there are 32 and 64 bit versions, versions for different browsers, and a lot more complications than for OS X. I have not heard from Wolfram technical support, but I am hopeful to do so in a couple days.

Both of those results are the same except for formatting. The form at the top is how it actually looks in the language and the bottom version is a pretty version that is a bit more readable. Both, however, should work the exact same.

There are a couple of minor issues which sometimes cause this. They only affect how it looks - they don't affect how it works.

Do these entities not work when you try to use them?

Hi Everyone,

I can (sort of) reproduce this. It works just fine on my computers (mostly all sorts of Macs running OS X). I am, however, admin of a site license and I have now found people who have this issue. On their computers (Macs, Windows) Entity and related commands to not evaluate properly - see below. The symptoms are similar to the ones described here. All computers can see the internet. We reinstalled Mathematica - taking care of all previous Mathematica related files on the computers; and, because we suspected an issue with a new version of Java, we also used different Java versions, with no conclusive results.

Here is what happens:

This is as opposed to:

This only appears to concern MMA 10.1. MMA 10.0.2 runs well on these machines. We also tried different scenarios with and without removing MMA10.0.2 first. We also checked whether it could be a slightly updated version of Mathematica's installer, as described here, but we could not find any correlation.

Cheers,

Marco

Hi,

try

EntityProperties["Mythology"]

Cheers,

M.