To avoid problems after installing or updating an extension please follow these steps in the correct order:
- Flush all Magento-caches
In "System -> Cache Management"
- Reindex all tables
In "System -> Index Management"
- Disable the Magento Compiler
In "System -> Tools -> Compilation", see also http://kb.magenting.com/content/24/81/en/disable-magento-compiler.html
- Log out from admin panel, then log in again
This prevents or resolves 404 errors in the Magento backend.
If the extension has been uninstalled and is now being re-installed, please check if the database has been cleaned up. In the table core_resource the entry [extensionname]_setup must be removed. Otherwise the install-scripts won't be executed again.
Modules for Magento 2 will usually have a README file in the module package. Follow the instructions from that README file to install the module.
- Make sure to follow all steps in the correct order.
- Do not skip any step or CLI command!
- For a Composer installation, all path names must be 100% correct in the file composer.json
- When installing from a ZIP / TGZ package, the path to the directory which contains the package must usually be given, not the path to the package itself.