When a font is included in a game but is not installed on the player's system, it sometimes completely disappears from buttons, labels etc. within the game's interface.
NEStalgia uses a custom font which we include in the compile by simply referencing it from within a DM file like so:
/var/NEStalgia_Font = 'NEStalgia.ttf'
That font is used for all of the interface labels and buttons, and usually works just fine:
Working example
However, the BYOND cache can apparently become corrupted and cause the text to disappear completely without defaulting to a backup font:
Broken example
This has happened in every version of BYOND released since NEStalgia development started a couple years ago. This bug has been reported before (but with less information provided).
Reproducing the Problem:
I've tried to create working demo to reproduce the problem, but I can't get the bug to trigger reliably. Although random, it does seem to happen much more often during remote server reboots and shut downs.
Most NEStalgia players get the bug when the game server shuts down or reboots. Upon occasion the bug can also be caused by logging into the game on two separate keys from the same computer and then closing one of the open DS windows. At that point the buttons/labels on the remaining DS window sometimes wipe immediately, and sometimes are just broken the next time the player logs in.
Operating system doesn't seem to be a factor: players using XP, Vista and 7 have all been hit.
When does the problem NOT occur?
The problem does not ever occur if the font in question is already installed on the player's system.
Workarounds:
When a player gets "bugged" with this issue, the only way to fix the problem is for them to clear their BYOND cache via the pager and then reboot their computer.
Your issue on the other hand I've seen before in one of Android Data's projects, but it was just the one time. I'm seeing what I can find out about it.