Magento Upgrade to 2.1.3 Module Disable Error

Question

After upgrading to Magento CE 2.1.3 (from 2.1.2) I am unable to disable a module through CLI. Issuing command

php bin/magento module:disable Module_Name

results in error:

 [Zend_Json_Exception]
Decoding failed: Syntax error 

any ideas?

Exception trace: () at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/zendframework1/library/Zend/Json.php:97 Zend_Json::decode() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/PackageInfo.php:85 Magento\Framework\Module\PackageInfo->load() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/PackageInfo.php:208 Magento\Framework\Module\PackageInfo->getRequire() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/DependencyChecker.php:132 Magento\Framework\Module\DependencyChecker->createGraph() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/DependencyChecker.php:95 Magento\Framework\Module\DependencyChecker->checkDependencyGraph() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/DependencyChecker.php:67 Magento\Framework\Module\DependencyChecker->checkDependenciesWhenDisableModules() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/Status.php:107 Magento\Framework\Module\Status->checkConstraints() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/setup/src/Magento/Setup/Console/Command/AbstractModuleManageCommand.php:92 Magento\Setup\Console\Command\AbstractModuleManageCommand->execute() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/symfony/console/Symfony/Component/Console/Command/Command.php:257 Symfony\Component\Console\Command\Command->run() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/symfony/console/Symfony/Component/Console/Application.php:874 Symfony\Component\Console\Application->doRunCommand() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/symfony/console/Symfony/Component/Console/Application.php:195 Symfony\Component\Console\Application->doRun() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Console/Cli.php:96 Magento\Framework\Console\Cli->doRun() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/symfony/console/Symfony/Component/Console/Application.php:126 Symfony\Component\Console\Application->run() at /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/bin/magento:23

Answer 1

Looks like that one of custom modules used in your application has incorrect syntax in composer.json.

For detect incorrect composer.json try debug Magento\Framework\Module\PackageInfo::load or put var_dump($key); before $packageData = \Zend_Json::decode($jsonData[$key]); in /vendor/mag‌​ento/framework/Modul‌​e/PackageInfo.php and run uninstall again