Hi Amit
I tried before and they didn't work, I just tried another 6 times and they still don't work, I'm not sure what "a few times" means.
My colleague has the original site for testing, but you could use All in One WP Migration to create a backup archive of the second site (I know that Duplicator doesn't work on WP Engine), and provide a link in the next reply to the archive (I'll enable private reply so that you can share a dropbox link or similar).
By "exception" I mean that it is a problem which is not generally reproducible, it appears to happen only on your particular site.
To demonstrate Avada working with Toolset on PHP 7 I set up an online server where you can see it in action.
I created a custom post type "Things" and made a template for single Thing posts using Avada. I stopped using the Avada page builder so that I could then edit the Content Template directly and wrap various sections of the fusion builder shortcodes with conditional shortcodes, in much the same way you have on your site.
I nested conditional shortcodes 3 levels deep and they worked without issue. (I am using simple conditions but the conditions themselves do not appear to be the problem, on my copy of your site I replaced all of the conditions with similar simple conditions and it didn't fix the problem).
You can see the results here: hidden link
That is generated by the following markup in the content editor:
[fusion_builder_container hundred_percent="no" hundred_percent_height="no" hundred_percent_height_scroll="no" hundred_percent_height_center_content="yes" equal_height_columns="no" menu_anchor="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" class="" id="" background_color="" background_image="" background_position="center center" background_repeat="no-repeat" fade="no" background_parallax="none" enable_mobile="no" parallax_speed="0.3" video_mp4="" video_webm="" video_ogv="" video_url="" video_aspect_ratio="16:9" video_loop="yes" video_mute="yes" video_preview_image="" border_size="" border_color="" border_style="solid" margin_top="" margin_bottom="" padding_top="" padding_right="" padding_bottom="" padding_left=""]
[fusion_builder_row]
[fusion_builder_column type="1_1" layout="1_1" spacing="" center_content="no" link="" target="_self" min_height="" hide_on_mobile="small-visibility,medium-visibility,large-visibility" class="" id="" background_color="" background_image="" background_position="left top" background_repeat="no-repeat" hover_type="none" border_size="0" border_color="" border_style="solid" border_position="all" padding="" dimension_margin="" animation_type="" animation_direction="left" animation_speed="0.3" animation_offset="" last="no"]
[fusion_text hide_pop_tinymce=""]So here is some text that is not inside any conditional to get us started.[/fusion_text]
[wpv-conditional if="( '1' eq '1' )"]
[fusion_text hide_pop_tinymce=""]Here is some text inside a Text Block module that is inside a conditional shortcode[/fusion_text]
[wpv-conditional if="( '2' eq '2' )"]
[fusion_text hide_pop_tinymce=""]Here is some text in a text module which is inside a nested conditional shortcode[/fusion_text]
[wpv-conditional if="('3' eq '3')"][fusion_text hide_pop_tinymce=""]And here is another text block in a text module, this time inside a double-nested conditional (i.e. 3 conditionals)[/fusion_text]
[/wpv-conditional]
[/wpv-conditional]
[fusion_text hide_pop_tinymce=""]Finally, here is another text block, this time inside the main conditional only.[/fusion_text]
[fusion_text hide_pop_tinymce=""]<p>Not forgetting, of course, the post content.</p>[wpv-post-body view_template="None"][/fusion_text]
[/wpv-conditional]
[/fusion_builder_column]
[/fusion_builder_row]
[/fusion_builder_container]
I used the same site credentials as you provided in your last private message so that you can check the set up yourself if you wish.
Exceptions like this are typically harder to pin down than general conflicts and bugs, but, in any case I've updated the internal ticket asking my colleague to prioritise finding a solution which he will hopefully be able to do soon.
If you make a copy of the second site available I will add that to the ticket.
