Can't set the port?!

in a recent change in the implimentation of my program, I've come across an absurd issue where I cannot set a roMessagePort to a variable I'm using to obtain a json string from a url. This is a vital part of my program that worked perfectly fine until this most recent change. If somebody could help me figure out what's gone wrong, I would appreciate it. I am absolutely clueless here!

[spoiler=the function involving the issue:1rzxtv5u]

Function GetJson(url as String) as string
    data = CreateObject("roString")
    port = CreateObject("roMessagePort")
    urlLink = CreateObject("roUrlTransfer")
    urlLink.SetMessagePort(port)      'the function crashes at this line, saying 
    urlLink.setUrl(url)                         '"dot opperator attempted with invalid brightscript component or interface reference"
    urlLink.SetCertificatesFile("common:/certs/ca-bundle.crt")
    urlLink.InitClientCertificates()

    if(urlLink.AsyncGetToString())
        finished = False
        while not finished
            msg = wait(0, port)
            if msg = invalid
                finished = True
                urlLink.AsyncCancel()
            else
                if type(msg) = "roUrlEvent"
                    finished = True
                    if msg.GetInt() = 1
                        response = msg.GetResponseCode()
                        if response <> 200
                            print "failure! response code "; response
                        else
                            data = msg.GetString()
                        end if
                    end if
                else
                    return invalid
                end if
            end if
        end while
    end if
    return data
end function

[/spoiler:1rzxtv5u]

[spoiler=code leading up to said issue:1rzxtv5u]

function GetServices()
	link_str = "url removed for privacy reasons"
	json_str = GetJson(link_str)
	json = ParseJson(json_str)
	recent = GetRecentSermons(json)
	return recent
end function

sub init()
'we can add a background here
'm.top.backgroundURI= some image url

m.layoutgroup = m.top.findNode("MainScreenGroup")
m.layoutgroup.setFocus(true)

devInfo = createObject("roDeviceInfo")
UIResolution = devInfo.getUIResolution()

lgr = m.layoutgroup.boundingRect()
lglr = m.layoutgroup.localBoundingRect()
x = -lgr.x + (UIResolution.width - lglr.width) / 2
y = -lgr.y + (UIResolution.height - lglr.height) / 2
m.layoutgroup.translation = [x, y]

m.services = GetServices()
...
end sub[/spoiler:1rzxtv5u]

[spoiler=Juuuuuuuust in case, this is the xml material involved:1rzxtv5u]<?xml version="1.0" encoding="utf-8"?>
<component name="MainScreen" extends="Scene">

<script type="text/brightscript" uri="pkg:/components/MainScreen.brs" />
<script type="text/brightscript" uri="pkg:/source/CreateLatestMenus.brs" />
<script type="text/brightscript" uri="pkg:/source/CreateLiveMenu.brs" />
<script type="text/brightscript" uri="pkg:/source/CreateRecentMenu.brs" />
<script type="text/brightscript" uri="pkg:/source/GetServices.brs" />
<script type="text/brightscript" uri="pkg:/source/GetTime.brs" />


<children>

<Group id ="MainScreenGroup">

<LayoutGroup
layoutDirection ="vert"
vertAlignment="center"
itemSpacings="[10]"
addItemSpacingAfterChild="true" >

<Button id="front"
text="Watch live service"
minWidth="1010"
height ="200"
showFocusFootprint="true"
/>

<LayoutGroup
layoutDirection ="horiz"
itemSpacings="10"
addItemSpacingAfterChild="true" >

<ButtonGroup id="buttonPairLeft"
rightJustify ="false"
minWidth ="500"
buttonHeight ="150"
buttons='["Recent Melbourne Services", "Recent Viera Services"]'
/>

<ButtonGroup id="buttonPairRight"
rightJustify ="false"
minWidth ="500"
buttonHeight ="150"
buttons='["Most Recent Sermons", "Sermons By Series"]'
/>

</LayoutGroup>

</LayoutGroup>

</Group>

</children>

</component>[/spoiler:1rzxtv5u]