OpenCart Community

yesterday i installed like 4 extensions (fb comments/ckeditor/socialogin/jgfbcomments), and somehow the multiseller features i have installed have been affected... taking me to a error 500 page after i add new products. i checked my error log and it seems like 4 lines from the multiseller extension are malfunctioning now, but it wasn't like this before. i have tried uninstalling the new extensions, refreshing modifications and clearing cache. but i'm still having that issue. everything was working properly before i installed new extensions. Do any of you have any idea how can i solve this/check what's wrong without reinstalling everything?

can you check in system/modification to see if any mods are altering the code for the multiseller extension?

i checked system/modification, and this is what i got:

<?xml version="1.0" encoding="utf-8"?>
<modification>
<name>Modification Default</name>
<code>default</code>
<version>1.0</version>
<author>OpenCart Ltd</author>
<link>http://www.opencart.com</link>
<file path="system/{engine,library}/{action,loader,config,language,template/}*.php">
<operation>
<search regex="true">
<![CDATA[~(require|include)(_once)?\(([^)]+)~]]>
</search>
<add position="replace">
<![CDATA[$1$2(modification($3)]]>
</add>
</operation>
</file>
</modification>


and i checked the page giving me error more carefully, and basically what has been affected is just the success alert. but the products are getting added despite seeing error 500 instead of success alert. I'm wondering if instead of the extensions, it could be the fact that i recently added "font-weight:bold" to the alert texts, although I don't see how a small change in style like that could have a big impact.

i would appreciate some insight. the multiseller lines that have been affected are these:

1: attributeautocomplete(attribute_row);
2: option_value_row++;
3: $('.date').datetimepicker({
4: $('.date').datetimepicker({
5: image_row++;
6: }

They all say the problem is undefined_variable: button remove