HI @Marvin_S 

Thanks for your reply - how the following fully answers your questions if not please come back to me.

The firmware is upto date - see screen shot below of the System - Firmware Uodate page.



I had narrowed down the ip address pool but now opened it back up so it is from xxx.xxx.xxx.1 to xxx.xxx.xxx.254

I have 18 mac addresses assigned specific IP address.
I did have 19 but deleted one and tried adding it back in but I got the same problem as the following screen shots
 

When you try to add an address reservation you get the screen as in next screen shot and if you are very quick you can enter the mac address

But the whole address reservation section goes grey after a few seconds as in next screen shot and you can't add any more information and the page freezes.
You have to click back on the left hand side menu to refresh the page to be able to do anything on the Lan Settings page.

This problem has been reported lots of times - surely a great company like TP-LInk muts have issued a fix?

many thanks

Neil

OK thanks Marvin_S
Just two  questions before I do that - the only notes about that one update I can do compared to the firm ware version I'm running say "Fix the bug of CWMP vulnerability."
1. Will doing this realy solve the problem I have reported in this thread as I've not would any other treads about this problem marked solved by doing this?

2. Will this update trash all the settings so will I have to start from scratch again and reset all the info in the router that allows it co connect to the internet. 

Thanks

Neil