Bug Report

Type /ver NametagEdit and post the output.
4.2.0

What version of Bukkit/Spigot/PaperSpigot are you using? Type /ver
PaperSpigot 1.8.8

What plugins are you using? Type /plugins
Plugins (57): CleanroomGenerator, PlaceholderAPI, NametagEdit, ConsoleSpamFix, CommandSync, ViaVersion, Tablist, CoreProtect, Essentials, SellWands, ClearLag, ViaRewind-Legacy-Support, MineSecure, Payout, WorldBorder, FactionCore, BuycraftX, Votifier, Multiverse-Core, ProtocolLib, NoCheatPlus, BlowableObsidians, VotingPlugin, FastAsyncWorldEdit, Vouchers, IPWhitelist, EssentialsChat, PermissionsEx, TNTFillFree, Vault, ViaRewind, HolographicDisplays, HideAndCustomPlugins, CoinFlip, AuctionHouse, PlayerVaults, EssentialsSpawn, GuiBalance, WorldEdit, PremiumVanish, LiteBans, CrateReloaded, DeluxeChat, CrazyEnvoy, WorldGuard, MobStacker2, CombatTagPlus, Factions, FactionsTop, GenBucket, FBasics, FactionsTopv5Hologram, KoTH, SilkSpawners, SilkSpawnersEcoAddon, ShopGUIPlus, CrazyEnchantments

Please explain your issue. How do you trigger it?
I'm using PlaceholderAPI by Clip. The placeholder %rel_factions_relation_color% won't work on the tab.
(It works in chat just fine with another plugin)

Are there any errors in the console? Please use: https://pastebin.com
No

Someone had a similar issue and now looking at the tag.

%rel_factions_relation_color%

Could this be cut off because of the character limit?

Not sure this issue still exists and this has been "in development" for 29 days.

NameTagEdit has to add compatibility with relational placeholders, here for more info:
https://www.spigotmc.org/resources/placeholderapi.6245/update?update=167267