You’re attempting to install ERPNext version 15 with Frappe version 16. This is not supported and will result in broken install. Switch to correct branch before installing.
The major versions must be the same. Why has it worked for you so far? I don’t know, but probably a new update to frappe version 15 is preventing what you want to do.
The 14 develop branch of erpnext doesn’t even exist anymore.
That it shows version 15 and 16 does not mean anything more than a typing error, not really relevant.