The following code reproduces the issue when run against a large JSON file (20+ MB in size).
DEFINE VARIABLE jsonObject AS Progress.Json.ObjectModel.JsonObject NO-UNDO.
DEFINE VARIABLE objectModelParser AS Progress.Json.ObjectModel.ObjectModelParser NO-UNDO.
ETIME (TRUE).
objectModelParser = NEW Progress.Json.ObjectModel.ObjectModelParser().
jsonObject = CAST(objectModelParser:ParseFile("SomeLargeJsonFile.json"),Progress.Json.ObjectModel.JsonObject).
MESSAGE "ETime: " ETIME SKIP
"Records: " jsonObject:GetJsonArray('SomeDataValue'):LENGTH
VIEW-AS ALERT-BOX.