Hello,
We recommend using the trial package on localhost and private networks. This package allows to run the Basic package functionality for testing purposes. The payment licenses will work fine on the choosen subdomain/domain/IP.
There's no known bug in phpdocx, so maybe your code had something wrong when using a previous version of phpdocx. A common mistake is not using the target option to set the scope of the placeholders to replace.
Regards.