I'm afraid I cannot open your job since I am currently using an older version of Talend. But it is clear that you are trying to create a folder that already exists using the mkdir command. Instead of using tSystem to create directories why not use a tLogRow to print out the directories it is going to create to see how the duplication occurs.
Also note, you are trying to create a directory called "null". This happens in Java when you are concatenating Strings and one of those Strings is null.
You need to refine your data collection and data validation.
You do not appear to be passing the value of input_row.newColumn1 to your output. You are setting your globalMap value (strangely to a key of "C:/outputFolder"....why?), but not passing the value to the output_row.newColumn1 column. Your tLogRow will be displaying this. We will need to see your tSystem configuration.
FYI the tFlowToIterate works by adding the row to the globalMap using the row name and column name as the key. Each iteration keeps those values for the whole of the flow of the iteration.
You do not need to do this. Below is a MUCH simpler way of achieving your goal.
1) Create the folder path String as before
2) Do not use a tSystem, use a tFileTouch component to create a file (you choose the name) in the folder you want to create. Select "Create direcory if does not exist".
3) Delete the file you have just created
There is no need to keep track of what folders you have create since this method will not error if you recreate the same folder.....because you cannot do that this way.
At the end of your path you need to add a filename (maybe "del.me"). This will create a file inside the folder. At the moment it is assuming your folder is a file. Once the "del.me" file is there, you can delete the "del.me" file.
