Um, yes, I have seen this too, in both Windows 7 and Linux.

What platform are you on?

I have raised a bug for this: https://bugzilla.mozilla.org/show_bug.cgi?id=1255770

Mine works properly after disabling the MoreFunctionsForAddressBook add-on.

Thanks for your replies Zenos, much appreciated.

We're on Windows 7 but has worked fine for years, just suddenly overnight seemed to change!

Thanks for raising the bug for us, we're not very technical.

How do I disable the MoreFunctionsForAddressBook add on. I have this listed under the tools menu but can't see where to disable it.

Thanks again.

Craig

In the Menu, Tools|Add-ons→Extensions.

Scroll down to MoreFunctionsForAddressBook and click its disable button.

To add some info, mine worked fine until I updated MoreFunctionsForAddressBook. So I think Kaosmos need to know.

Hmmm have disabled the MoreFunctionsForAddressBook but still not resolved the problem :-(

My apologies, this HAS resolved the problem, forgot to restart Thunderbird before checking!

Now let with no additional functions but never mind, can cope with that.

Thank you very much for your help, have a great weekend.

Craig :-)

Gnospen said

To add some info, mine worked fine until I updated MoreFunctionsForAddressBook. So I think Kaosmos need to know.

Yes, I've now removed this and it's working again so there must be a bug. Now without additional search features :-(

Zenos has reported a bug.

Thanks for your responses :-)

I have emailed Kaosmos. Thanks everyone for the feedback and other info.

New version available now.

https://freeshell.de/~kaosmos/morefunctionsforAB-TB3-0.7.4.1.xpi

That's great, thanks once again for your help with this, much appreciated.

After updating to TB 45 (April 2016) I started having this problem of not being able to search the address book. I have the latest version of More Functions for Address book 0.7.4.1. I'm really disappointed in Mozilla. I know they said they don't want to do anymore development on TB, but why break what already works? I refuse to use Outlook and I don't like Google's stuff so I don't know where to turn to find an email/calendar program that someone supports. I'd even pay for it.

Its ones again MFFAB. Last time Kaosmos had made some adjustments in advance so it would work with the coming TB45.x Sadly that didn't work with TB38.x so he had to changed it back, That's the MFFAB ver 0.7.4.1 I have the same problem and its temporarly fixed when you turn of MFFAB