See if there's something in the MODX error log (on the Reports menu) around the time of the error.
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PLEASE, PLEASE specify the version of MODX you are using.
MODX info for everyone:
http://bobsguides.com/modx.html
I ran into the same issue. Then I realized it was because Articles 1.6 requires MODX 2.2.1 and I am running 2.2.0.
Unfortunately the package does not validate whether you are running the required version of MODX. Not sure if that's possible.
Thanks for the responses!
1. The error.log contains errors referring to allow_url_fopen (see below). That is enabled (and I haven't had problems installing other packages). I believe this is a known issue with Articles but this was happening before, when Articles 1.4.7 was working.
2. I am running 2.2.0 -- so I guess I should try to upgrade, if what lukemcd says is correct. I had the same or very similar error trying to install 1.5, though. Did that also depend on 2.2.1?
Regarding updating, it seems I should untar the modx package over the existing installation, making sure not to overwrite config.inc.php or the core/components/ directory. Anything else I should be careful about?
Meanwhile, the site is unavailable, so I'm trying to deal with this as quick as I can!
Here are the errors, which I don't think are the problem in this case:
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not transfer package getpage-1.2.2-pl.transport.zip to /var/www/vhosts/www.radicalimprov.net/core/packages/.
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not open file for reading: getresources-1.4.2-pl.transport.zip?revolution_version=Revolution-2.2.0-pl2
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) MODX could not download the file. You must enable allow_url_fopen, cURL or fsockopen to use remote transport packaging.
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not transfer package getresources-1.4.2-pl.transport.zip to /var/www/vhosts/www.radicalimprov.net/core/packages/.
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not open file for reading: quip-2.3.0-pl.transport.zip?revolution_version=Revolution-2.2.0-pl2
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) MODX could not download the file. You must enable allow_url_fopen, cURL or fsockopen to use remote transport packaging.
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not transfer package quip-2.3.0-pl.transport.zip to /var/www/vhosts/www.radicalimprov.net/core/packages/.
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not open file for reading: taglister-1.1.7-pl.transport.zip?revolution_version=Revolution-2.2.0-pl2
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) MODX could not download the file. You must enable allow_url_fopen, cURL or fsockopen to use remote transport packaging.
[2012-04-11 15:21:01] (ERROR @ /connectors/workspace/packages.php) Could not transfer package taglister-1.1.7-pl.transport.zip to /var/www/vhosts/www.radicalimprov.net/core/packages/.
Make sure your core/packages directory is writeable and has the correct ownership.
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PLEASE, PLEASE specify the version of MODX you are using.
MODX info for everyone:
http://bobsguides.com/modx.html
I got a similair error when upgrading from 1.5.1 (installing this gave errors) to 1.6.0.
Core/packages is writable. Ownership is set by hostingprovider (I can not change that, other packages installed without problems from scratch).
Please look at the attachment.
If you need more information, just let me know.
Maurice.
I've got the exact same error...
I upgraded to 2.2.1 and that fixed the problem.
Thanks lukemcd!