Prestashop giving error whenever I click Modules & Services

[Rana Abdullah]

I am using Prestashop 1.6.1.20. Whenever I click Modules and services, it gives me following error.
Parse error: syntax error, unexpected 'use' (T_USE) in /home/fiaokr2iosoy/public_html/classes/module/Module.php(1361) : eval()'d code on line 27
[PrestaShop] Fatal error in module file :/home/fiaokr2iosoy/public_html/classes/module/Module.php(1361) : eval()'d code:
syntax error, unexpected 'use' (T_USE)

I tried to upgrade my prestashop from 1.6 to 1.7 and after that this error started.  There are many addons which only works with the latest version so that's why I tried to upgrade. I also tried to find solutions but all of them are too advance. If anyone can help me or show me a better link to solve this error, it will be a great help. 

[Rhobur]

That is most likely due to you using a PHP version not supported by PS1.6+, revert to PHP7.0/7.1