Merge the vcf files into a single file: https://support.mozilla.org/en-US/questions/1280605

I did that in the command prompt, but don't see in their folder where that changed anything, and when I tried to import again I still had the same problem. What am I missing?

So, you ran the command in the folder with all the vcf files, and the merged.vcf (or whatever name you specified) wasn't created?

How do you run the cmd in a specific folder? I'm not aware of how to do that.

When you launch the cmd window (Windowskey+R, type cmd), it will probably open in

C:\Users\username where username is your Windows user name. To go to a subfolder, type e.g.

cd downloads

and you will then be in the C:\Users\username\downloads folder

Repeat if your vcf are in a subfolder of downloads. Type cd.. to go up a level in the folder structure.

https://www.computerhope.com/issues/chusedos.htm

Okay. I did all that (not in downloads but "Documents" then subfile "WLMContacts" where I had downloaded the VCF files. I then typed copy *.vcf merged.vcf , and it appeared to do it. However, when I am in TB and try to import from that very directory and folder, it still will only do one at a time. Am I doing something wrong? BTW, thanks for your quick help.

Is the merged.vcf about the size of the combined .vcf files? Did you import from Tools/Import...Address books...vCard file... select merged.vcf?

I think I'm missing something. When I did the cmd vcf merge, where does that merged vcf file reside after that? I'm still importing from Tools/Import Address book, vCard file but going to the original location to import them. After having merged them in cmd, should I be going somewhere else to import them from?

The merged.vcf file is in the same folder as the source vcf files. Follow the instructions, starting from Tools/Import in TB, and select the merged.vcf file in the final step.

Okay, after researching I finally figured out that merged file is HIDING in the other contacts files. I looked for the one with the largest size and found it. Thanks for all your help. It's very much appreciated.

I have almost the same problem. I'm trying to import my contacts from Windows Live Mail on my old Windows 7 computer to Thunderbird on my new Windows 10 computer. I've downloaded the contacts as .vcf files on a thumb drive and plugged that into the new computer. I've clicked on my Thunderbird address book and selected to import from vcf files, and all my contacts are displayed individually. But there are hundreds and it will only allow me to transfer 1 at a time. Is there a way to do all at once? I saw the above explanation about merging but I'm not quite following that. Is this something I do after I've got the thumb drive plugged into my new computer?

Yes, you must merge the .vcf files before importing the merged .vcf into TB. That can be done by launching a cmd window and navigating to the thumb drive, merging the files, then importing the resulting vcf file that contains all the contacts.

Thanks. You know back in the '70's they didn't teach any of this stuff, and I have no kids. So I see how to launch a cmd window from above. Do I do this on the new computer with the thumb drive installed? How do I navigate to the thumb drive from the cmd window please?

You can do the merge on either computer, wherever the flash drive is. Use the cd.. and cd commands to navigate up and down the folder structure, as explained in the computerhope link.

I am having the same problem. I merged all vcf files(over 5000!) to one and imported that big single vcf file. It worked for appx. 300 contacts and than gave an error. I was only until "Alicia.." . Is there a max of VCF files to import. Or is there something else wrong.

I'm not aware of any limit on importing vcf files, and a file with 5k contacts doesn't seem like a huge resource burden. What was the indicated error, and was it shown in the Error Console (Ctrl+Shift+J)?

You could try importing with the CardBook add-on.

Will CardBook work for me? I tried to install it but Firefox said it was unverified and prevented installation. Sorry but I'm not following what you're talking about with the cd command and navigating.

Will CardBook work for me? I tried to install it but Firefox said it was unverified and prevented installation. Sorry but I'm not following what you're talking about with the cd command and navigating.

Install CardBook in TB, not Firefox.

https://support.mozilla.org/en-US/kb/installing-addon-thunderbird

See the computerhope link above for command line help.