Erro ao encerrar Dialog

Bom dia!

Estou com problema para encerrar um Dialog :D

Eu tenho um fwmarkbrowse dentro de um fwlayer dentro de um msdialog, e criei um botao fechar, ao clicar em fechar o seguinte erro ocorre:

argument #0 error, expected C->U, function upper on CANUSEGED(FWMBROWSE.PRW) 13/09/2023 17:37:37 line : 3527

Só consigo fechar o dialog sem erros caso clique no botao x na barra superior direita do dialog :/

Segue parte do código:

DEFINE MSDIALOG oDialog TITLE "TESTE"  FROM 0, 0 TO nJanAltu, nJanLarg PIXEL

oFwLayer := FwLayer():New()
oFwLayer:init(oDialog,.F.)

oFWLayer:addLine("TIT", 10, .F.)
oFWLayer:addLine("COR", 90, .F.)

oFWLayer:addCollumn("COLEMP"    ,       025, .T., "TIT")
oFWLayer:addCollumn("COLFIL"    ,     025, .T., "TIT")
oFWLayer:addCollumn("COLEST"    ,     025, .T., "TIT")
oFWLayer:addCollumn("COLBTN"    ,     025, .T., "TIT")
oFWLayer:addCollumn("COLGRID",      100, .T., "COR")

oPanEmp     := oFWLayer:GetColPanel("COLEMP"         ,  "TIT")    
oPanFil          := oFWLayer:GetColPanel("COLFIL"         ,  "TIT")
oPanEst          := oFWLayer:GetColPanel("COLEST"         ,  "TIT")
oPanBtn        := oFWLayer:GetColPanel("COLBTN"         ,  "TIT")
oPanGrid       := oFWLayer:GetColPanel("COLGRID"        ,  "COR")

aAllEmp := FwAllCompany()
cCBoxEmp := aAllEmp[1]
oComboEmp := TComboBox():New(014,002,{ |u|if(PCount()>0,cCBoxEmp:=u,cCBoxEmp)},aAllEmp,100,20,oPanEmp,,{||Alert('Mudou item da combo')},/*bValid*/,,,.T.,,,,/*bWhen*/,;
    ,,,,'cCBoxEmp','Empresa:',1,/*oLabelFont*/,/*nLabelColor*/)

aAllUnit := FwAllUnitBusiness(cCBoxEmp)
cCBoxFil := aAllUnit[1]
oComboFil := TComboBox():New(014,002,{ |u|if(PCount()>0,cCBoxFil:=u,cCBoxFil)},aAllUnit,100,20,oPanFil,,{||Alert('Mudou item da combo')},/*bValid*/,,,.T.,,,,/*bWhen*/,;
    ,,,,'cCBoxFil','Unidade de Negocio:',1,/*oLabelFont*/,/*nLabelColor*/)

aAllEst := FwIAllEst(cCBoxEmp,cCBoxFil)
cCBoxEst := aAllEst[1]
oComboFil := TComboBox():New(014,002,{ |u|if(PCount()>0,cCBoxEst:=u,cCBoxEst)},aAllEst,100,20,oPanEst,,{||Alert('Mudou item da combo')},/*bValid*/,,,.T.,,,,/*bWhen*/,;
    ,,,,'cCBoxEst','Estado:',1,/*oLabelFont*/,/*nLabelColor*/)    

oMrkBrowse := FWMarkBrowse():New()
oMrkBrowse:SetOwner(oPanGrid)
oMrkBrowse:SetDescription("Teste")
oMrkBrowse:SetMenuDef("")
oMrkBrowse:SetIgnoreARotina(.T.)
oMrkBrowse:ForceQuitButton(.T.)
oMrkBrowse:DisableConfig()
oMrkBrowse:DisableReport()
oMrkBrowse:DisableDetails()
oMrkBrowse:SetWalkThru(.F.)
oMrkBrowse:oBrowse:SetUseFilter(.F.)        
oMrkBrowse:oBrowse:SetFieldFilter(aFiltro)
oMrkBrowse:SetAlias(cAliasTemp)
oMrkBrowse:SetColumns(aColumns)

oMrkBrowse:SetFieldMark("MARK")
oMrkBrowse:SetMark('X', cAliasTemp, "MARK")
oMrkBrowse:SetAllMark( { || .T. } )
oMrkBrowse:bAllMark := { || InvertSel(cAliasTemp,oMrkBrowse:Mark(),lMarcar := !lMarcar,.F. ), oMrkBrowse:Refresh(.T.)  }

oBtnSair     := TButton():New(014, 061, "Fechar", oPanBtn, {|| oDialog:End()}, nLargBtn, 018, , oFontBtn, , .T., , , , , , )
oBtnSalvar     := TButton():New(014, 122, "Salvar", oPanBtn, {|| oDialog:End()}, nLargBtn, 018, , oFontBtn, , .T., , , , , , )

oMrkBrowse:Activate()
Activate MsDialog oDialog Centered
oTmpTable:Delete()