I am using 4.8.0  and would like to have users retrieve password by giving their email ( as in a previous post by the method below)

requiresUniqueEmail field in the web.config file to true ( requiresUniqueEmail="true" ). The web.config file is located in the root folder of your DNN installation.

To find out if your portal enables retrieve password using email address check the REquiresUniqueEmail option under User Accounts Settings.

My Question is   As I did not have the setting <requiresUniqueEmail> set to unique when the webite went live and now have over 1,000 users. can I simply ensure no emails are duplicate in the database and then set the <requiresUniqueEmail> to true. or will I cause a problem or even crash my site??

any help appreciated.

Many thanks

many thanks for the prompt reply,  having reviewed the thread  I dont think I will try..  

Regarding upgrading, I would love to but the thought fills me with dread having seen several coments here and on other DNN sites of the issues it raises.

Have I missed out on an easy and effective way of upgrading that does not entail lots of manual interventions?

Whilst the site is fairly  vanilla, I am concerned that fixing issues might, (because of my lack of experience and knowledge) involve expensive outside help...

your thoughts, suggestions and comments ,however scathing of my concern and ineptitude would be welcome

Here is a script to find duplicate emails (I have 964!!!):

select email, count(*)  AS NumOccurrences
from users
group by email
having count(*) >1
order by NumOccurrences DESC

I need to make a plan on how to change them...

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