Fatal error: Uncaught Error: Call to a member function getJournalId() on null in /home/u498302959/domains/dinastirev.org/public_html/classes/issue/IssueAction.inc.php:31 Stack trace: #0 /home/u498302959/domains/dinastirev.org/public_html/classes/search/ArticleSearch.inc.php(274): IssueAction->subscriptionRequired(NULL, Object(Journal)) #1 /home/u498302959/domains/dinastirev.org/public_html/plugins/generic/recommendByAuthor/RecommendByAuthorPlugin.inc.php(142): ArticleSearch->formatResults(Array) #2 /home/u498302959/domains/dinastirev.org/public_html/lib/pkp/classes/plugins/HookRegistry.inc.php(107): RecommendByAuthorPlugin->callbackTemplateArticlePageFooter('Templates::Arti...', Array) #3 /home/u498302959/domains/dinastirev.org/public_html/lib/pkp/classes/template/PKPTemplateManager.inc.php(1540): HookRegistry::call('Templates::Arti...', Array) #4 /home/u498302959/domains/dinastirev.org/public_html/cache/t_compile/a4fc84a2d9d2a85c011fcc528f09577e88e2fcff^1c372c95cd85572e0fbc9a53d0323a0b229cfc78_0.app.frontendpagesarticle. in /home/u498302959/domains/dinastirev.org/public_html/classes/issue/IssueAction.inc.php on line 31