Root cannot be edited error

I am trying to clear all the transactions and company names in my EPPNext next account, so that I can start with a fresh new database.

I removed all transactions for my test company, and I then deleted that “test” company from Accounts. I now have no companies or transactions listed in Account - which is what I wanted.

However, now I do not seem to be able to create a new company and save it. I can enter the Company details but when I press save I get the following error “Root cannot be edited. Did not save.”

Is there anyway of resolving this or have I screwed up the Account completely?

Using version 6.24.5 on Windows 10 laptop using Edge browser.

@SVS just start with a new site / VM