For anyone planning to use the latest (64-bit) version of Paratext (9.1), you will need to ensure that you are also running the latest version of PTXprint (1.4.2 or later) - as older versions don’t even start up.
There have been several improvements and lots of bug fixes since 1.3 was released back in October - so it is definitely worth updating to this latest version.
Note that the Help is a little bit easier to find, and users are encouraged to help each other using this forum before filing GitHub issues.
