Please help 2017 error, not in 2016

[maxhunter]

In 3DsMax 2016 my script works ok no warning messages... in 3DsMax 2017 i get this:

-- MAXScript Rollout Handler Exception:
-- Type error: getClassInstances requires MAXClass, got: undefined
-- MAXScript callstack:
-- thread data: threadID:6548
-- ------------------------------------------------------
-- [stack level: 0]
-- In ShadersSimple(); filename: F:\MAXTO\_Source\Max\Xml_Export_3_55.ms; position: 108222; line: 2955
-- Locals:
-- VRayMtl: undefined
-- matArray: undefined
-- Externals:
-- owner: undefined
-- ------------------------------------------------------
-- [stack level: 1]
-- called from Export01(); filename: F:\MAXTO\_Source\Max\Xml_Export_3_55.ms; position: 138857; line: 3839
-- Parameters:
-- option: 1
-- Locals:
-- listmat: #()
-- selObj: #($Target_Camera:TempCam @ [-153.093109,-153.093109,124.999985], $Target:TempCam.Target @ [0.000000,0.000046,0.000000])
-- option: 1
-- tempPath: "C:\Users\marce\AppData\Local\Temp\"
-- selected: undefined
-- newfilename: "___EXPORTED"
-- Externals:
-- c02_BakeShaderAll: Global:c02_BakeShaderAll : c02_BakeShaderAll()
-- c04_uniqueBumpValue: Global:c04_uniqueBumpValue : c04_uniqueBumpValue()
-- count_cam: Global:count_cam : 2
-- doPatches: Global:doPatches : doPatches()
-- fixBlendToStd: Global:fixBlendToStd : fixBlendToStd()
-- ShadersSimple: Global:ShadersSimple : ShadersSimple()
-- c03_vrtostd: Global:c03_vrtostd : c03_vrtostd()
-- removeDisplacements: Global:removeDisplacements : removeDisplacements()
-- simp_MakeUnique: Global:simp_MakeUnique : simp_MakeUnique()
-- userPath: Global:userPath : "C:\Users\marce\Documents\TEMP3D"
-- c01_Simplifier: Global:c01_Simplifier : c01_Simplifier()
-- Export02: Global:Export02 : Export02()
-- simplifyVray2Sided: Global:simplifyVray2Sided : simplifyVray2Sided()
-- owner: undefined
-- collectAllSingleMaterial: Global:collectAllSingleMaterial : collectAllSingleMaterial()
-- newcam: Global:newcam : <Deleted scene node>
-- MakeUniqueBlue: Global:MakeUniqueBlue : MakeUniqueBlue()
-- ------------------------------------------------------
-- [stack level: 2]
-- called from StartExport(); filename: F:\MAXTO\_Source\Max\Xml_Export_3_55.ms; position: 141356; line: 3956
-- Parameters:
-- option: 1
-- Locals:
-- filename: undefined
-- t: undefined
-- option: 1
-- fullname: undefined
-- f: undefined
-- toFilename: undefined
-- ii: undefined
-- Externals:
-- Export_FixMaterialName: Global:Export_FixMaterialName : Export_FixMaterialName()
-- Export_FixTextureName: Global:Export_FixTextureName : Export_FixTextureName()
-- maxFileName: SystemGlobal:maxFileName : ""
-- Export01: Global:Export01 : Export01()
-- CollapseMeshModifiers: Global:CollapseMeshModifiers : CollapseMeshModifiers()
-- userPath: Global:userPath : "C:\Users\marce\Documents\TEMP3D"
-- Export_FixObjectName: Global:Export_FixObjectName : Export_FixObjectName()
-- owner: undefined
-- ------------------------------------------------------
-- [stack level: 3]
-- called from btExpStart.pressed(); filename: F:\MAXTO\_Source\Max\Xml_Export_3_55.ms; position: 144815; line: 4070
-- member of: Rollout:rXMLExport
-- Locals:
-- Externals:
-- xmlDoc: Global:xmlDoc : dotNetObject:System.Xml.XmlDocument
-- chOp2: RolloutControl:chOp2 in rollout:rXMLExport : CheckButtonControl:chOp2
-- rXMLExport: Global:rXMLExport : Rollout:rXMLExport
-- theEdittext: RolloutControl:theEdittext in rollout:rXMLExport : EditTextControl:theEdittext
-- chOp0: RolloutControl:chOp0 in rollout:rXMLExport : CheckButtonControl:chOp0
-- userPath: Global:userPath : "C:\Users\marce\Documents\TEMP3D"
-- StartExport: Global:StartExport : StartExport()
-- configPath: Global:configPath : "F:\MAXTO\_Source\Max\\config.xml"
-- owner: Rollout:rXMLExport
-- data: Global:data : dotNetObject:System.Xml.XPathNodeList
-- chOp1: RolloutControl:chOp1 in rollout:rXMLExport : CheckButtonControl:chOp1
-- ------------------------------------------------------
-- [stack level: 4]
-- called from top-level

[Swordslayer]

Looks like you don't have Vray installed...