Array operation attempted on variable not DIM'd

here is the array

Function ShowPosterScreen(videos as object) as integer
 posterScreen = CreateObject("roPosterScreen")
    port = CreateObject("roMessagePort")
    posterScreen.SetMessagePort(port)

contentList = CreateObject("roArray",25, true)
    for each video in videos
        poster = CreateObject("roAssociativeArray")
         poster.ShortDescriptionLine1 = video.Title
            poster.SDPosterURL = video.Image
            poster.HDPosterURL = video.Image
            contentList.push( poster )
    end for


    posterScreen.SetContentList( contentList )

here is the json

Function LoadJSONFile() as void
    jsonAsString = ReadAsciiFile("pkg:/json/sample1.json")
    m.json = ParseJSON(jsonAsString)

    ShowPosterScreen(m.json.Videos)
End Function

this is what I get when i used the print statement

------ Running ------
SpringBoardButton Pressed: 5 index: 1
<uninitialized>
1
BrightScript Micro Debugger.
Enter any BrightScript statement, debug commands, or HELP.
'
'
Array operation attempted on variable not DIM'd. (runtime error &he7) in ...kg:/source/AppSpringboard.brs(40)

040: print videos[msg.getindex()]
Backtrace:

I had 20 in the array but 21 videos so I move it to 25
also print videos.count() gives the following error

'Dot' Operator attempted with invalid BrightScript Component or interface reference. (runtime error &hec) in ...kg:/source/AppSpringboard.brs(40)

040: print videos.count();
do you think my problem is

 ShowPosterScreen(m.json.Videos)