Fails with this this message:

I dont seem to be able to replicate this. I have just edited this one no problem. Could I ask how you are editing? Click and hold the title?

Sorry, yes, it's when using click and hold.

I would advise upgrading as on my 4.7.1 test site, I am unable to reproduce this.

Do you have any plugin/application that is related to Topics or Topic Manager or something else? Because sometimes when a plugin/application is out of date it my cause some problems if they are specific to what you are trying to do. I'm saying this because It happend to me.

I'm not entirely sure what's causing this problem, but If you want I can have a look for you. 

Please also let us know what browser and operating system you are using, along with confirming you are using our latest release

Many thanks, can confirm that the problem is gone after upgrading.

Thank you for letting us know 🙂