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

• KAndy: can you add -vvv to command and post stack trace
• Devtype: @KAndy added above :)
• Max: i think that one of custom modules used in your application has incorrect syntax in composer.json. Try debug Magento\Framework\Module\PackageInfo::load or put var_dump($key); before $packageData = \Zend_Json::decode($jsonData[$key]); in /var/www/vhosts/mydomain.co.uk/cfw.mydomain.co.uk/vendor/magento/framework/Module/PackageInfo.php and run uninstall again
• Devtype: @MaxStsepantsevich appreciate the answer it helped me to figure out the module with invalid composer.json. If you can post this as an answer I'll be able to mark it as answered, cheers :)
• Max: i did it, thx :)

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