Troubleshooting

Problem	Why, and what to do
No design of the pack is in the shop, or none goes on (version 1.0.0)	1.0.0's data/zaiders_overlays.xml has no collection name (the <nameHash>zaiders_overlays</nameHash> line after </presets>). The game loads the file but can't use any of its designs, and ZAIDERS Appearance says the game does not have collection zaiders_overlays in F8. Update to 1.0.1: copy its data/zaiders_overlays.xml and fxmanifest.lua over yours and keep your config.lua, restart the server and reconnect. See Updating.
The designs aren't in the tattoo shop	Check that ensure zaiders_tattoos is in server.cfg and that the console shows it starting. Then follow your script's steps in Your tattoo script: some need its list. A player who was already in the server when the pack started must reconnect. With ZAIDERS Appearance, look at F8: the game does not have collection zaiders_overlays means version 1.0.0 (see the row above).
A design shows its code instead of its name	That script doesn't read the names the pack gives the game. Its list has the names: install it with zaiders_tattoos_install.
Other players don't see my tattoos	Check that OneSync is on, not legacy (otherwise the console says so when the pack starts). With Config.DiagCommand = true, /zaiderstattoos shows who syncs, whether your tattoos were sent and what the players around sent. See What other players see.
Other players see a tattoo lighter than I do	It was put on more than once, to darken it. Only ZAIDERS Appearance sends those layers; this pack shows each tattoo once.
Other players see wrong tattoos (from the base game or other packs)	Leave Config.FixTattooSort = true.
Another tattoo pack also shows its tattoos to other players	Turn off the other pack's sync: this one shows every tattoo, from every collection. If you turn this one off instead (Config.Sync = false), nobody else sees this pack's tattoos unless ZAIDERS Appearance syncs them.
A design shows twice in the shop	Another resource with the same designs is running (an older copy of this pack). Leave only zaiders_tattoos.
Other players see the tattoos I'm trying on in another shop	That shop has no screen with the mouse or scripted camera while trying them on. Its script can call exports.zaiders_tattoos:setBusy(true) when it opens and setBusy(false) when it closes. With ZAIDERS Appearance syncing, the pack passes it on: the same call works either way.
My tattoos vanished for everyone after another menu	That menu took them off your ped, and the pack shows the others what your ped wears. Put them back in that menu.
The installer says it couldn't write	Add the add_filesystem_permission line it prints to server.cfg (before ensure zaiders_tattoos) and restart the server, or copy the file from install/ as the console says.
The installer says a file isn't plain JSON	That file has comments, a trailing comma or a BOM, which FiveM can't read. Fix it (or save it as UTF-8 without BOM) and run zaiders_tattoos_install again.
The console says no known tattoo script found	No known tattoo script is running. If yours reads the game's own tattoo shop, it already works. If it's a known one under another folder name, type zaiders_tattoos_install <script> <folder>. Otherwise use integrations/<language>/generic/zaiders_tattoos.json. See Any other script.
The console says ZAIDERS Appearance: running, but its tattoo shop is off	Its Config.Tattoos.enabled is false (it does not sell this pack), or a resource from its Config.Tattoos.owners runs (... while <script> runs). In the second case that script sells the tattoos: install this pack's list there with zaiders_tattoos_install.
The console says not installed yet or the installed list is from an earlier version of this pack	Type zaiders_tattoos_install in the server console.
The console says the installed list was changed on this server	Designs were removed or added in that script's list, so the installer leaves it as it is. zaiders_tattoos_install force replaces it with the pack's and keeps a backup.
The console says this version has no list for addon tattoos	That version of the script has no file for addon tattoos (the message names it): fivem-appearance without tattoos.json or files/tattoos.json, or vMenu older than 3.8.8. Update it, or use the generic list in integrations/<language>/generic/.
The console says Config.ListsLanguage must be es or en	Set it to en or es. Meanwhile it uses en.

Still stuck?

Send us the console lines that mention zaiders_tattoos (from the server start) and which tattoo script you use.