i read through this thread, and it's complicated to understand even for a computer professional (non network admin computer professional)
the problem is the manuals and online guides for filezilla server give a lot of unnecessary information, and filezilla server is not set up to work "out of the box" with the vast majority of computers. i think a concise guide to fix the faq problems is a great place to start, instead of pointing users to disable/allowprograms in windows firewall (which is unnecessary after windows98 to do. even a partially disabled windows firewall allows fz to work)
the 2 major problems i surmise users would not know is:
1. you "have" to enter a username AND PASSWORD to share folders (without going into detail about ways around this)
2. assuming https://ftptest.net//
shows your server no problem and you still cannot access your server remotely, i believe the solution is to use passive mode, which means opening up another port (or range of ports)
i'm not saying i'm ungrateful for a free ftp server solution with so many customizable options. i'm saying if there are things which can be easily fixed, they should be fixed. it's a shame with so much good open source software, the most popular open source ftp server solution there is no pop up box or simple instructions in the filezilla settings/users which explain common problems. i'm sure for people who have network certs and work in networking this isn't a big deal bc it's obvious, however you want to make your software work easily for the non expert, not make the software work easily for the expert. expert users could simply copy some config file when setting up fz many times, whereas beginner fz users want to get fz working without reading long manuals on a website where 90% of the things they read aren't pertinent to their problem.
i'm simply suggesting to direct users to webpages with concise pertinent solutions to the main problems first, not directing users to general networking or manual webpages written by fz devs with all information included while using fz.
as a disclaimer, a lot of people appear to have different problems and solutions. most of these problems can be fixed by reworking default settings in fz server and adding text in settings/users which explains common problems and solutions. i would have to agree what boco writes is argumentative probably defending fz, when fz is far from a perfect piece of software. just bc there are a lot of man hours put into making fz, does not mean it's without its major problems.