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Firewall causes Rails update failure in NetBeans

If you are receiving the following error message when trying to update Rails in NetBeans 6.7:

ERROR: While executing gem … (Gem::RemoteFetcher::FetchError) SystemCallError: Unknown error – An established connection was aborted by the software in your host machine (

…try momentarily disabling your firewall. In my case, Windows Firewall seemed to be torpedoing the process: after disabling it for a moment, the update went through perfectly.

Perhaps obvious, but also easily overlooked.

Credit: This post by “joseph george” reminded me to check the firewall settings.

NetBeans 4.1 with Windows 7 RC x64

Had some issues when I tried to install NetBeans 4.1 from the Open University CD-ROM, which is not surprising, considering its age and the determination of the Open University to keep on using legacy software.

First of all, the installer wouldn’t display correctly, with many graphical elements not appearing at all. Thanks to Simon over at, I was able to get past this by forcing Windows 2000 compatibility mode.

Secondly, when going to File -> Open in NetBeans, Java crashed. This appeared to be a complete show-stopper. I even set up Windows XP Mode just to run it correctly. However, while I was doing that, I realised that the problem could lie with the Java Runtime: the Open University installer had installed the x86 version of the Java Runtime and the JDK. So I tried uninstalling the x86 versions and installing the Java SE Runtime Environment 5.0u19 and likewise the Java SE Development Kit 5.0u19 instead for Windows x64.

Upon installing NetBeans threw a paddy because it couldn’t find the JDK. I had to go to C:/Program Files (x86)/netbeans-4.1/etc/, set the permissions on the folder for Users to Write, and then edit the appropriate line in the netbeans.conf file to the following: netbeans_jdkhome=”C:\Program Files\Java\jdk1.5.0_19″. Then it was a case of putting the permissions on the folder back to as they were.

Upon restarting NetBeans, all seemed to be well…and so far, all is still well. As a bonus, using this version of the Java Runtime/JDK doesn’t force Windows 7 out of the Aero GUI. I’ll keep you posted if there are any further developments.

Having said all that, though…I really hope the Open University get a move on and switch to NetBeans 6.5 or later! It’s faintly ridiculous that courses that teach such a platform-independant technology as Java are so prescriptive of the platforms they will support.