Product Tags Error when Editing with "View All” button.

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https://arastta.org/forum/product-tags-error-when-editing-with-view-all%E2%80%9D-button-nan-error-occur#reply-3853

Environment
-This error has been reproduced using a fresh install of 1.6.2. on php 7.0 and php 5.4
a)both in a subdirectory and
b) in the root directory on a live hosted domain.
-Log in as
a) Admin as well as
b) another user profile with privileges that sufficed to add or edit products.
-The issue occurs using either Basic or Advanced views.

• The issue occured with both of two languages active as well as with one inactive.

Steps to reproduce:
Log in and go to:

1. Products > Edit > Tags
   Assuming there are tags move on to step 2, else
   Ad a new tag, say mytag1, mytag2. Click plus to add and save. Once tags have confirmed as added by refreshing the front end, proceed with step 2

2. Click View all and touch tags with the mouse. It is enough to click a tag, then click apply. It made no difference if there is no change made like delete a tag. Save or save close.
   Refresh and review tags.
   Either a “NaN” or “1” value or multiple ones have appeared.
   There are also entered into the DB table.

Adding a new product or editing an existing one, new or existing tags made no difference, the tags are corrupted and altered.

NaN entry cannot be deleted from the interface.

Purging the data using Export/Import back and forth does not change the behaviour observed.

Not repro:
Adding tags manually without touching the View All does not trigger this issue in our trials.

Logs with multiple entries of the errors message below were logged, however they stopped logging after a numer of times even though the tag error itself continued to reproduce.

2018-03-17 10:57:32 - PHP Notice: Undefined variable: applied in /home/emoda/public_html/stg/admin/view/template/common/show_all.tpl on line 32