NoMethodError in Welcome#full_list

Showing /home/ubuntu/amr-distribution/app/views/welcome/full_list.html.erb where line #44 raised:

undefined method `each' for nil:NilClass
Extracted source (around line #44):
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43
44
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<% row_color = 'odd'%>
<% fade_direction = 'Left'%>
<% @product_categories.each do | product_category | %>
<tr class="transcend-tr<%= row_color %> wow animate__animated animate__fadeIn<%= fade_direction %>">
<% row_color = (row_color == 'odd' ? 'even' : 'odd') %>
<% fade_direction = (fade_direction == 'Left' ? 'Right' : 'Left') %>

Rails.root: /home/ubuntu/amr-distribution

Application Trace | Framework Trace | Full Trace

Request

Parameters:

{"category"=>"Networks%20%26%20Security"}

Response

Headers:

None