I for one am stumped. It shouldn't happen. Typically you'd get `invalid` from `createObject` if it failed to create what's requested. I thought maybe you created too many URLs - then i typed some code in console to create 10,000 roUrlTransfer but canceled it out of patience - still it created 3569 objects just fine:
BrightScript Debugger> a = [] : for ii=1 to 10000 : a.push(CreateObject("roUrlTransfer")) : next
^C
BREAK (runtime error &hf8) in $LIVECOMPILE(73)
BrightScript Debugger> ? ii, a.count()
3570 3569
BrightScript Debugger> ? a[3500]
<Component: roUrlTransfer>
BrightScript Debugger> a[3500].SetUrl("http://blog.roku.com/developer")
BrightScript Debugger> bscs
roArray: 14
roAssociativeArray: 106
roByteArray: 1
roGlobal: 1
roImageCanvas: 1
roInt: 2
roList: 8
roMessagePort: 8
roString: 187
roUrlEvent: 8
roUrlTransfer: 3579
Total # components: 3915
How does it act if you type in console your 2-line snippet, after the run was interrupted by the error?