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Open edX - Login/Register submit button disabled after the first fail attempt

The default login/registration form of Open edX has a bug that will disable the submit button after the first fail attempt and seem like no one want to fix it. Fortunately, you can use the combined login/registration form which does not have that bug. You enable it by add this under the FEATURES list inside /edx/app/edxapp/lms.env.json:


Then restart your apps and enjoy:

$ /edx/bin/supervisorctl restart all

OpenStack - Kolla-Ansible prechecks error "Hostname has to resolve to IP address of api_interface"

Following the OpenStack Kolla Ansible documentation I was trying to check my kolla ansible environment by running this command:

sudo kolla-ansible prechecks

And I got this error:

TASK [rabbitmq : fail] ***************************************************************************************************************************************fatal: [localhost]: FAILED! => {"failed": true, "msg": "The conditional check 'item.stdout.find(hostvars[item['item']]['ansible_' ~ hostvars[item['item']]['api_interface']]['ipv4']['address']) == -1' failed. The error was: error while evaluating conditional (item.stdout.find(hostvars[item['item']]['ansible_' ~ hostvars[item['item']]['api_interface']]['ipv4']['address']) == -1): 'dict object' has no attribute 'api_interface'\n\nThe error appears to have been in '/usr/local/share/kolla-ansible/ansible/roles/r…

Open edX - Course about page not found on LMS and how to fix

If you click on a course from the LMS and it says "Page not found", your properly should check this variable in /edx/app/edxapp/lms.env.json and cms.env.json:


It should not be the same with LMS_BASE. For example: your LMS_BASE is "", so the CMS_BASE should be something like "" not "". So check and change the variable if you got page not found error, then restart your stack, everything will be back to normal.

To install VMWare Workstation 12 Pro on Ubuntu 16.04.3 successfully

In order to successfully install VMmare Workstation 12 Pro on Ubuntu 16.04.3 you have to use at least version 12.5.3. That release of VMware Workstation has fixed the kernel (4.10) incompatibility issue in Ubuntu 16.04.3.

Download link: