Alternate Strategy to Update ERPNext to current ~v11

ERPNext
8

The branch your apps are set to mismatch - frappe is on master while erpnext is on develop.

Try this:

bench switch-to-branch master erpnext --upgrade

For help check these out

https://discuss.frappe.io/search?q=TypeError%3A%20the%20JSON%20object%20must%20be%20str%2C%20not%20%E2%80%98bytes%E2%80%99