melding question

[Kirika-]

Hi I have been off the game for awhile and missed a few updates
I just got to the end of shadow bringers and started taking a closer look at my gear.
what is with this materia that says

"cannot be melded past the first advance slot"
I cannot seem to meld them at all even at an npc ,

so do I not have gear with advance slots?

First, see this post, to help explain the different Materia restrictions and types:
https://forum.square-enix.com/ffxiv/...=1#post5337963

Materia Meld NPC's can not do Advanced Melding, only players can learn that skill via a quest, and only after learning Melding.
Fortunately, players with Advanced Melding skill can perform that skill on other's gear via a special interface. Right click on a player's target bar, who will help with melding, and choose Request Meld from the menu.
This will open the interface.
All you do is place the gear item and the materia into the interface, then that player will attempt the meld. Basic melding is 100% success, Advanced Melding has an increasing rate of failure depending on the materia level and how far into the advanced meld non-open holes (slots) you are going (up to 5 total slots).
Failing an advanced meld destroys the materia that was used in the attempt, but doesn't effect the gear.