Our plugin does not contain any reference to OMSC_PLUGIN_PATH_URL
so your issue is definitely not caused by our plugin. Please try to selectively disable other plugins until you find the one which is triggering that error. Alternatively you may perform a full text search on your plugins folders to locate it.
I got this problem after updating to version 1.3.0 and it appears the conflict is with Olevmedia Shortcodes. Any ideas on what I can do to fix this?
This issue is caused by Olevmedia Shortcodes plugin, which does not support the widgets editor integration.
You should make the following changes:
1. In file /olevmedia-shortcodes/functions/button.php
replace
if( 'post.php' != $pagenow && 'post-new.php' != $pagenow )
with
if( 'post.php' != $pagenow && 'post-new.php' != $pagenow && 'widgets.php' != $pagenow )
2. In file /olevmedia-shortcodes/functions/interface.php
replace
if( 'post.php' != $hook && 'post-new.php' != $hook )
with
if( 'post.php' != $hook && 'post-new.php' != $hook && 'widgets.php' != $hook )