Fatal error: Uncaught Error: Function name must be a string in /enfold/framework

Hi,
I got a fatal error all of sudden as below : can you tell me why and how to fix it? As a matter of fact, I have one main site, jjkim.com, and sub-domain for korean site: kor.jjkim.com, and newly created test site : test.jjkim.com The error occurred in main and test both, but Korean site is working ok without the error. There was the error on the home page and contact us, and wp-admin doesn’t show correctly enfold setting sub-pages. I copied theme folder from korean site to main and test site, and disappeared the error on home page, but still error in contact us sub-menu. The my enfold version is 3.06, do you think I should upgrade to the latest version to fix the problem??? This is a critical and please help me to fix. thank you.

Fatal error: Uncaught Error: Function name must be a string in /homepages/17/d549585728/htdocs/test.jjkim.com/wp-content/themes/enfold/framework/php/class-form-generator.php:194 Stack trace: #0 /homepages/17/d549585728/htdocs/test.jjkim.com/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/contact.php(345): avia_form->create_elements(Array) #1 /homepages/17/d549585728/htdocs/test.jjkim.com/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/shortcode-template.class.php(250): avia_sc_contact->shortcode_handler(Array, ‘\n[av_contact_fi…’, ‘av_contact’, Array) #2 /homepages/17/d549585728/htdocs/test.jjkim.com/wp-includes/shortcodes.php(326): aviaShortcodeTemplate->shortcode_handler_prepare(Array, ‘\n[av_contact_fi…’, ‘av_contact’) #3 [internal function]: do_shortcode_tag(Array) #4 /homepages/17/d549585728/htdocs/test.jjkim.com/wp-includes/shortcodes.php(223): preg_replace_callback(‘/\\[(\\[?)(av_con…’, ‘do_shortcode_ta…’, ‘<br />\n[av_cont…’) #5 /homepages/17/d549585728/htdocs/te in /homepages/17/d549585728/htdocs/test.jjkim.com/wp-content/themes/enfold/framework/php/class-form-generator.php on line 194

admin–enfold theme error: http://www.jjkim.com/wp-admin/post.php?post=7&action=edit

Fatal error: Uncaught Error: Access to undeclared static property: AviaHtmlHelper::$element in /homepages/17/d549585728/htdocs/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/html-helper.class.php:123 Stack trace: #0 /homepages/17/d549585728/htdocs/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/html-helper.class.php(32): AviaHtmlHelper::render_element(Array) #1 /homepages/17/d549585728/htdocs/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/meta-box.class.php(140): AviaHtmlHelper::render_metabox(Array) #2 /homepages/17/d549585728/htdocs/wp-admin/includes/template.php(1045): MetaBoxBuilder->create_meta_box(Object(WP_Post), Array) #3 /homepages/17/d549585728/htdocs/wp-admin/edit-form-advanced.php(686): do_meta_boxes(Object(WP_Screen), ‘side’, Object(WP_Post)) #4 /homepages/17/d549585728/htdocs/wp-admin/post.php(173): include(‘/homepages/17/d…’) #5 {main} thrown in /homepages/17/d549585728/htdocs/wp-content/themes/enfold/config-templatebuilder/avia-template-builder/php/html-helper.class.php on line 123