I have had the same Panasonic (land line) phone for years- and suddenly the handset isn't recognized by the base ("no link to base. Move closer to base and try again") Phone is plugged in as usual- and the speaker phone works fine to answer or to initiate a call.

Is it a cortless ?try this; put the phone into the base then this connect the power and the phone line then reconnect them

When mine were first setup and going through the setup steps (Language. Time etc) one of the steps was linking to base and it just asked yes or no and I said yes.

I just had this problem and I found the answer. Reregister the handset with the base.

You might need instructions to figure out how to do it but there should be an option on the phone settings to connect back up to the base. It will resync the base and the phone and everything will work gloriously again.

If the re-registration doesn't work, your handset is probably shot. You can buy a reconditioned one on eBay for under $30.

Thanks very helpful info. TIP: Location key on my phone base is labeled as the "Transfer" key. In my case the registration did not initially work until I pulled out and reinserted the battery. Try this before you purchase a replacement handset.

I was having this problem and my base wasn't plugged in. Lol. Make sure the base is plugged in or else the cordless won't work. The cordless have there own little charging base but the large non cordless base needs to be connected and plugged in. Silly me!

I will try it right now

I tried all of the above and it did not work for my phone behaved just as described above, though mine would do it intermittently. What "seemed" to work this time was to clear the window display of "number of missed calls". Once I did that everything started working again. It may be coincedental but worth a try before tossing the phone.

Had the same issue. Solved it by reregistering the base as explained here :

http://www2.panasonic.com/consumer-electronics/support/Phones-Fax/Telephones/DECT-6-0-Phones/How-To-Guides/model.KX-TG4011N.H#ts

I am sure many people just trash the phone when it happens
Error message should be more explicit !

Many different troubleshooting sites all suggest resetting base by unplugging power and telephone cords from base foe a minute or re-registering handset to base. I tried all of these to no avail so I called Panasonic support and got the same answers PLUS check batteries. I KNEW it could NOT be the batteries as all 3 handsets were failing at the same time. Boy, was I WRONG. After buying a new Panasonic phone, I was installing it and putting the supplied batteries in the new handsets when I thought I would just try puttting the new batteries in my old handset and it worked and now all 3 handsets work perfectly. A similar report was filed in YOUTUBE with 4 handset batteries all not working. Mine were 2 years old and I guess they do not last forever even though they are rechargeable. I was going to keep the new phone anyway but found that the speakerphone in the base of the KXTG 4133N would not allow answering calls but only listening to messages so I returned it.
I could have just said "REPLACE THE BATTERIES" but I thought the background would be useful.

Err, well, I had the same problem, decided to try a "reboot" took the battery out, left if for 2 minutes and glory be, it works again!!

I was able to resolve this.
The phones lost registration to base.
On the handset
Menu --> Initial setting --> Registration --> Register Handset
Go to base press locator button for 5 seconds