Can't install my own custom modpack

[Prototype958]

God I hate that I have to post this here, but I've been at this for hours and can't seem to figure out what I'm doing wrong..

I've gone through what I believe to be the correct steps in building my modpack.zip file and creating the modpack on my account, but when I go to install it from the launcher I get the error:

"Error unzipping a file for the following pack: Prototype958 Custom

Attempting to extract file prototype958-custom-1.0.zip, but it did not exist.

Plase consult the modpack author."

Now, I'm not sure what this "prototype958-custom-1.0.zip" file is supposed to be, my file in dropbox is modpack.zip.

This pack is intended to just be something for me to play personally, and maybe if I can ever get it working, to bring a buddy in as well. I copied the Tekkit mods folder and added a couple additional ones that aren't in there that I like such as Tinkers, Morph and a few other small ones. Nothing huge, but it still contains all the current Tekkit mods, and should have all of the core modes necessary

 

To build the pack, these were the steps I used to build the folder:

1. Created a folder on my desktop called "modpack"

2. In modpack I created "bin" and "mods"

3. In the mods folder I copied in all the mods from the tekkit mods folder exactly as they are in there. I also copied a couple additional mods from Icehenge.

4. I downloaded the latest version of Forge universal for Minecraft 1.64 (because that's what all the mods I have are for)

5. Zipped "bin" and "mods", I made sure the file was named "modpack.zip" and was archived as a zip file (using WinRar)

6. Uploaded it to dropbox as modpack.zip

7. Created the modpack "Prototype958 Custom" on my technic account. Set to hidden

8. Updated the modpack and included the dropbox share link: https://www.dropbox.com/s/tdcikb475k142u7/modpack.zip?dl=1

(Also tried it as dl=0 and https://dl.dropbox just to see if it would work)

 

When I copy the link from "My Modpacks" and enter it to the launcher, it finds the pack but attempting to install gives me the error I listed above... 

 

I appreciate any help, thanks ahead of time.