Although most of Drupal core objects and strings can be translated with the Internationalization (i18n) package, contributed modules are a different story and some of them present specific issues. For administrative purposes, we will be handling core issues as 'bugs' and compatibility issues with other contributed modules as 'support requests'. This is a list of known issues and workarounds.
Using Domain Access with Internationalization will cause multiple issues so first of all please think twice if you really need to use both of them. (Each domain having a different language doesn't mean you really need i18n, unless you are actually sharing some multilingual data between domains). Some of the issues:
- Variables per domain and multilingual variables may clash, see #1307058: Use new Variable API for different variables per domain.
- Translation of user defined strings may need some workarounds, see #745540: Conflict with i18nstrings (user defined strings not being translated on some sites / to some languages)
- And maybe more, http://drupal.org/project/issues/domain?text=i18n&status=All
Internationalization and Entity Translation are compatible, though for each content type you will need to select one or the other, with one exception:
Multilingual select (i18n submodule) is not compatible with Entity Translation enabled nodes, they will be filtered out randomly from pages and menus.
The current search blocks defined in code are not able to be translated unless they are explicitly saved.
#1403082: Strings in configurations read from code are not able to be translated
Menu items are not translated or displayed for all languages.
#1236450: Translated menu items show in all languages [Nice Menus]
It seems both modules try to replace the same menu items.
#1233804: compatability with panels on NODE / ADD form
There are specific tokens defined by i18n, all of them starting with 'i18n-'. These tokens are translated equivalents of the original ones.
#1177084: Translated vocabulary names not working with Pathauto
Internationalization's Taxonomy Translation submodule overrides some standard taxonomy pages. This feature isn't be compatible with other modules doing the same, such as:
There are multiple issues with View field widgets and filters not being translated. You should use the Internationalization Views module to address these issues.
Both modules replace the node translation tab so the 'select existing translation' feature won't work.