Error in Component Manager /componentGrid/components 500 (Internal Server Error)

[dannyalfonzo]

To open http://umc2.magento.loc/setup/index.php/componentGrid/components

said:

RuntimeException
File:
/home/dannyalfonzo/www/umc_mg2/setup/src/Magento/Setup/Model/PackagesData.php:88
Message:
Couldn't get available versions for package ultimatemodulecreator/umc-base

What can i do? Magento Version 2.1.7

Thanks

[dannyalfonzo]

I have been reading on the net, apparently it is a magento bug with extensions that are not in the magento marketplace

What I did was delete composer.json and composer.lock all reference to the umc-base package, and it works again, but is this correct?