New tiles types

Hello. Long time ago...

Here is my problem : I would like to create news tiles type (for [false] example lava, snowy sand, snowy cobblestones). I could obviously create sceneries and use them, but for large surface 1) It will be long and borring 2) They will now react correctly toward light (or won't react if I tick "don't light").

Creating the art files was quite simple, they are technically perfect (based on real tiles using Artview). The matter is : how to add them in the game.
1) I think have have to add it in Art/tilename.mes (see spoiler to see the document)

Spoiler: tilename.mes

// NOTE: any 3-letter tile name prefix can have flags after the
// name, following a / character. Valid flags are:
// b - tile blocks critter motion
// f - tile blocks critter motion but allows flying
// s - critters sink in this tile
// i - icy or slippery tile, critters may fall down
// n - natural (not man-made) tile
// p - soundproof (or almost so), sounds are deadened thru this tile
//
// After the name and any optional flags, put a space and a number. The
// number is the sound type that footsteps will make on this type of
// tile. Valid numbers are
//
// 0 dirt
// 1 sand
// 2 snow
// 3 stone
// 4 water
// 5 wood
//
// For clarity, please place a number. If it is missing however, a 0
// will be assumed.


// Outdoor flippable tile names start here, at 0
{0}{drt/n 0} Dirt
{1}{grs/n 0} Grass
{2}{rck/n 3} Rocky Ground
{3}{snw/n2} Snow
{4}{dg1/n 0} Dead Grass 1
{5}{bg1/n 0} Bog Shore 1
{6}{bg2/s/n 4} /s Bog Shore 2
{7}{bog/s/n 4} /s Bog Water
{8}{sw1/n 0} Shallow Water 1
{9}{sw2/s/n 4} /s Shallow Water 2
{10}{sw3/s/n 4} /s Shallow Water 3
{11}{swr/s/n 4} /s Shallow Water
{12}{dwr/f/n 4} /f Deep Water
{13}{rok/b/n/p 3} /b Solid Rock
{14}{WK1 3} Side Walk 1
{15}{WK2 3} Side Walk 2
{16}{ST1 3} Street1
{17}{WD3 5} Outdoor Wood Planks
{18}{Dst/n 1}Desert
{19}{ssd/n 1}Shallow Sand
{20}{dIs/n 1}Desert Island
{21}{Jdt/n 0}Jungle Dirt
{22}{Jgr/n 0}Jungle Grass
{23}{SxW/f 0} /f Sea Wall
{24}{sod/f 4} Outdoor sewer
{25}{TS1 3} Tarant Street 1
{26}{TS2 3} Tarant Street 2
{27}{TDt/n 0} Tordded Dirt
{28}{Blk/b/p 0} /b Black Yall
{29}{VDR/n 0} Void Dirt
{30}{FOG/b} Void Fog

// Outdoor non-flippable tile names start here, at 100
{100}{TST 0}
{101}{Prh 5}
{102}{Dks 5}
{103}{TLa 3} Tulla walkways
{104}{VWK 0}
{105}{ICE/i/n 3}

// Indoor flippable tile names start here, at 200
{200}{fl1 3}
{201}{wod 5}

// Indoor non-flippable tile names start here, at 300
{300}{Dn1 3}
{301}{WI1 3}
{302}{Dn2 3}
{303}{CF1/n 0} Cavern Floor 1
{304}{WD1 5}
{305}{Sew/s 4} Sewer Water Floor
{306}{WD2 5} Dark Wood Floors
{307}{ILL 0} Illegal Tiles
{308}{Dir/n 0} Dirt Indoor Floor
{309}{cf2/n 0}
{310}{STD 3} //Dungeon Floors
{311}{VFL 0} //VoidFloors
{312}{JIN/n 0} //Jungle Dirt inside
{313}{Blk/b/p 0} /b Black Yall

// Edges start here, at 400
// Note you only have to list an edge once. If you add a line
// called GRSDRT, you don't need a DRTGRS (although it's OK
// to have it, it's redundant)

{400}{drtgrs}
{401}{drtrck}
{402}{rcksnw}
{403}{drtdg1}
{404}{drtbg1}
{405}{bg1bg2}
{406}{bg2bog}
{407}{drtsw1}
{408}{sw1sw2}
{409}{sw2sw3}
{410}{sw3swr}
{411}{swrdwr}
{412}{drtrok}
{413}{drtWK1}
{414}{drtWK2}
{415}{drtST1}
{416}{drtWD3}
{417}{drtDst}
{418}{swrssd}
{419}{ssddIs}
{420}{dIsJdt}
{421}{JdtJgr}
{422}{drtsod}
{423}{drtSxW}
{424}{drtTS1}
{425}{TS1TS2}
{426}{drtTDt}
{427}{drtBlk}
{428}{drtTST}
{429}{drtPrh}
{430}{dwrDks}
{431}{dIsTLa}
{432}{DrtFOG}
{433}{DrtVDR}
{434}{VDRVWK}
{435}{SnwICE}

But adding a number 31 (even a copy of a previous line) prevent WorlEd to run. So, where should I add it too ?
In terrain/terrain.mes ?
I guess there is other files that I did not found.

Any idea/solution please ?
Thanks you