7-Zip Add to zip doesn't work

I have 7-Zip, version 16.04 (64-bit). I can open an archive & drag files into it. However, when I press the green plus sign, I get a message that the operation is not supported. There must be some setting that controls this, but I can't find it. Here's the message I get:

I would appreciate any advice.

I think this post should be moved to the end of
Make Open Archive the default for 7Zip
because my default is 7z.exe & I see that @dalchina has 7zFM.exe as the default. Not sure how I did this.

Locate the file 7zFM.exe and right click then run as admin.

Set like this:

Tools> Options

I get that message too. Just close the window and re-open the zip. You will see that files were added.

That green plus sign usage:

Run 7zFM.exe as admin.

In the window that opens browse to the files or folder that you want to add then click the green plus sign.

Callender said:

That green plus sign usage:

Run 7zFM.exe as admin.

In the window that opens browse to the files or folder that you want to add then click the green plus sign.

Thank you for your help (Sorry for the delay in responding; I had to run errands). I set my options as you mentioned in your previous post. I see that I can run 7zFM.exe as admin to open a window & then I can use the green + to add files.

However, when I click on an existing zip file, I can add to it by dragging a file into it, but I can't click the green + sign to add anything. Is that something that isn't supported by 7z?

Also, I changed part of the registry when looking at Dalchina's post here: Make Open Archive the default for 7Zip

My registry now looks like this after changing 7z.exe to 7zFM.exe in the registry:

I notice that the key still says 7z & not 7zFM. Did I associate it incorrectly?

Thank you again!

phrab said:

However, when I click on an existing zip file, I can add to it by dragging a file into it, but I can't click the green + sign to add anything. Is that something that isn't supported by 7z?
Also, I changed part of the registry when looking at Dalchina's post here: Make Open Archive the default for 7Zip

My registry now looks like this after changing 7z.exe to 7zFM.exe in the registry:

I notice that the key still says 7z & not 7zFM. Did I associate it incorrectly?

Thank you again!

I don't have that registry key and if I click a zip file it opens in 7zFM.exe

I have:

As far as I know the green plus sign id for creating a new archive.

Existing archives - files can be added via drag 'n' drop.

For me it works the same as you describe. If I open an existing archive and click the green plus sign I get the same error.

This is what the add button is for:

Using the free zip compatible 7-Zip package - Tutorial 3 | Top Windows Tutorials

So it's for adding files to a new archive that you want to create.

It's not for adding files to an existing archive.