composer.json error: Unable to unserialize value

[miller75]

I am using the following to remove a module

php -d memory_limit=2048M bin/magento module:uninstall Elastomatic_SortCatalogWidget --clear-static-content

Unfortunately I get an error In PackageInfo.php line 100:  Elastomatic_SortCatalogWidget composer.json error: Unable to unserialize value. Error: Syntax error

I have tried various solutions including editing the Json.php as this page https://magento.stackexchange.com/questions/194010/magento-2-2-unable-to-unserialize-value/196825#19... 

But I have had no luck

[Sunil Patel · Accepted solution]

Hello @miller75 

if you installed module manually into app/code then remove manually from app/code and find related table from db and remove it manually.

Then do 

php bin/magento setup:upgrade