Joomla Update extension compatibility improvements

Improved language string about “Update Information Unavailable” extensions

administrator/language/en-GB/com_joomlaupdate.ini

@@ -112,7 +112,7 @@ COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_RUNNING_PRE_UPDATE_CHECKS_NOTES="<p>Ple
 COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_SHOW_LESS_COMPATIBILITY_INFORMATION="Less Details"
 COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_SHOW_MORE_COMPATIBILITY_INFORMATION="More Details"
 COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_UPDATE_SERVER_OFFERS_NO_COMPATIBLE_VERSION="Update Information Unavailable"
-COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_UPDATE_SERVER_OFFERS_NO_COMPATIBLE_VERSION_NOTES="Extension does not offer a compatible version for the selected target version of Joomla. This could mean the extension does not use the Joomla update system or the developer has not provided compatibility information for this Joomla version yet."
+COM_JOOMLAUPDATE_VIEW_DEFAULT_EXTENSIONS_UPDATE_SERVER_OFFERS_NO_COMPATIBLE_VERSION_NOTES="<p>Joomla cannot detect the extension's compatibility with the target version of Joomla. This could mean one of the following:</p><ul><li>the extension does not use the Joomla update system</li><li>the developer has not provided compatibility information for this Joomla version yet</li><li>Joomla failed to retrieve the update information or your server experienced an error</li><li>the extension is part of a package but Joomla has not recorded this information properly e.g. because the extension was installed using the Discover installation method.</li></ul><p>Please check the corresponding developer's site to determine the compatibility information with the target version of Joomla.</p>"
 COM_JOOMLAUPDATE_VIEW_DEFAULT_NON_CORE_BACKEND_TEMPLATE_USED_NOTICE="We detected that you are not using a core admin template. You might find the upgrade process smoother if you <a href='index.php?option=com_templates&view=styles&client_id=1'>switch</a> to use the %s template."
 COM_JOOMLAUPDATE_VIEW_DEFAULT_HELP="More Information"
 COM_JOOMLAUPDATE_VIEW_DEFAULT_INFOURL="Additional Information"