excel - vba issue with error handling -

all informations sheets explained here. i'll explain quickly:

i have 3 sheets (plan1, banco , db). plan1 has named ranges insert information , information stored on banco , copied bd (this last 1 saves past informations while banco has last information inserted).

i have code verify if named range alocacao exists on bd , if exists, they're load again on plan1. after this, can change name of alocacao after inserting new name in range named substituit_aloc using code below:

sub substituirproduto_click() dim foundcell range, firstaddr string, fnd string, newaloc range, long  on error goto catch      fnd = sheets("plan1").range("alocacao").value     set newaloc = sheets("plan1").range("substituir_aloc")      set foundcell = sheets("bd").columns(5).find(what:=fnd, _         after:=sheets("bd").cells(rows.count, 5), lookat:=xlpart, _         lookin:=xlformulas, searchorder:=xlbyrows, searchdirection:=xlnext)      if not foundcell nothing         firstaddr = foundcell.address     end if      until foundcell nothing         = + 1         foundcell.value = newaloc.value          set foundcell = sheets("bd").columns(5).findnext(after:=foundcell)         if foundcell.address = firstaddr or >= 30             exit         end if     loop  catch: msgbox "substituido!"  end sub 

sometimes works , gets:

run-time error 91: object variable or block variable not set

and highlithed line:

if foundcell.address = firstaddr or >= 30 

despite error, need without influencing end result. added on error goto catch doesn't show error message , finishs run code, i'm still getting error message.

someone know why still showing error message without being catched error handling?

if not foundcell nothing   if foundcell.address = firstaddr or >= 30      exit   end if end if