I know this issue has been asked before on both the CB and Kunena forums, but I have not found a real solution yet and am hoping you might have come across a fix, since you use Kunena on the Joomlapolis website.

I have an long-time established website with Community Builder and Kunena Forum integrated very nicely, but when you compose a new topic or reply on the Kunena forum, the PREVIEW box does not work. It is just blank (please see attached screenshot).

When I disable the Kunena - Community Builder Integration plugin the Preview box works fine.

This problem began when I performed a major upgrade (Joomla, CB, Kunena, and changed template). I have almost 10,000 registered CB users, so moving forward without the CB-Kunena integration is not an option for me.

Joomla 3.6.5
Community Builder 2.1.0
Kunena 5.0.5
K2 2.7.1

Thank you!

Thank you for the reply.

Here is the results of the Developer Tools Console when I click the PREVIEW button. Does this mean that is a JQuery problem?

jquery-migrate.min.js:2:542
JQMIGRATE: Migrate is installed, version 1.4.1 jquery-migrate.min.js:2:542

jquery.min.js:4:26272
Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user’s experience. For more help xhr.spec.whatwg.org/ jquery.min.js:4:26272

send @ jquery.min.js:4
ajax @ jquery.min.js:4
kPreviewHelper @ edit.js:17
(anonymous) @ edit.js:43
dispatch @ jquery.min.js:3
r.handle @ jquery.min.js:3

jquery.min.js:2:24932
Empty string passed to getElementById().

- - - -

Here are the results I get when I look at the console for the Joomlapolis Forum when I hit the Preview button:

jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:12739
JQMIGRATE: Migrate is installed with logging active, version 1.4.1

jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:6
Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check xhr.spec.whatwg.org/.

send @ jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:6
ajax @ jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:6
kPreviewHelper @ jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:8707
(anonymous) @ jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:8733
dispatch @ jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:5
r.handle @ jscss.php?f=c384019…&type=js&gz=gz&d=1&i=0:5

I resolved this issue for my installation. Hopefully the EASY fix I came across will be helpful to others.

Under GLOBAL CONFIGURATION > SYSTEM tab, I had the CACHE SETTINGS set to "OFF - CACHING DISABLED". When I changed it to "ON - CONSERVATIVE CACHING" the Preview functionality started working.

I cleared the cache and purged expired as well.

Thanks for your help with this issue.