Exception class: RuntimeException()

Unable to write in the cache directory (/home/www/system/cache/twig/3b).

File: /home/www/vendor/twig/twig/src/Cache/FilesystemCache.php
Line: 61


Backtrace:

#0 /home/www/vendor/twig/twig/src/Environment.php(409): Twig\Cache\FilesystemCache->write()
#1 /home/www/vendor/twig/twig/src/Environment.php(381): Twig\Environment->loadClass()
#2 /home/www/vendor/twig/twig/src/Environment.php(359): Twig\Environment->loadTemplate()
#3 /home/www/vendor/twig/twig/src/Environment.php(333): Twig\Environment->load()
#4 /home/www/system/pages/memory_game.php(41): Twig\Environment->display()
#5 /home/www/system/router.php(265): require('/home/www/syste...')
#6 /home/www/index.php(108): require_once('/home/www/syste...')
#7 {main}