pagination error in taxonomy: Warning: Division by zero

$per_page is $number_of_performers, which must be an incorrect value.

PS: Also you can reduce your $sort_array defines with:

$sort_array = array();
$alphas = range('A', 'Z');
foreach ($alphas as $lttr)
   $sort_array[$lttr] = __($lttr,'framework');

UPDATE

furthering @tom-j-nowell point of $total_terms being the problem – your codes wp_count_terms()‘s second argument is supposed to be an array or a string query, not an integer like $offset is.

While troubleshooting, it may benefit to see the math and variable values so you can get a better idea what is the problem. Above your .paginator.lighter echo, I’d add:

echo "<pre>
total_terms = {$total_terms}\n
per_page = {$per_page}\n
---
total = ".($total_terms/$per_page)."</pre>";