After an unsuccessful attempt to download a video (for any reason), the next attempt is not possible due to an error

> After an unsuccessful attempt to download a video (for any reason), the next attempt is not possible due to an error 
I used the wrong video link. After using the correct link, the video and audio downloaded, but the formation of a single file does not occur due to the error:

> After an unsuccessful attempt to download a video (for any reason), the next attempt is not possible due to an error 
After any unsuccessful attempt to run the program, an error appears:

Having the same problem
```bash
zaqueo@mapache:~$ ./vimeo-dl -i "https://31vod-adaptive.akamaized.net/exp=1699898087~acl=%2F9623fbc8-c3af-4e18-aa8d-fa2568f3d14e%2F%2A~hmac=a26c47dad47d2be7cf6f3dec8aa803393dc8da92066b4fe23a9b824ddae15f2f/9623fbc8-c3af-4e18-aa8d-fa2568f3d14e/sep/video/2961fbf1,4ef88d62,5489b398,63eb560e,b240ca77/audio/3f39fbe8,b422eff1,ff355f89/master.json?base64_init=1&query_string_ranges=1" --video-id "b240ca77" --audio-id "3f39fbe8" --combine --user-agent "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36"
Error: invalid character '<' looking for beginning of value
```
Will check out the code maybe I can find the error and maybe make a hotfix
PD: Trying in ubuntu. Will test with Windows now.
`Error: invalid character '<' looking for beginning of value`
Is it a common Go issue when parsing HTML with JSON (or a the string `<nil>`, but whatever).
It's a Cloudflare spambot protection page that prevent access to the main json file (the one that got every data about the segments of the videos).
**The solution**: Just get the `master.json` and give it to vimeo-dl. Instruction:
- From the "Network tab" of the development tools (Ctrl + Shift + E on Firefox, I guess it's F12 + Click on the Network tab).
- Found the URL of the `master.json` file.
- Right click => Copy URL.
[vimeo-dl](https://github.com/akiomik/vimeo-dl) can have this json URL as input. (`vimeo-dl -i JSON_URL`).
I got in the end a `Conversion failed!` error but at least I have the video and the audio. 🤷
**Edit**: I can confirm that `ffmpeg -i video.mp4 -i audio.mp4 -c copy video_merged.mp4` worked instantly. For my use-case I don't need to search more. Maybe [yt-dlp/yt-dlp](https://github.com/yt-dlp/yt-dlp) can support master.json too. I will check it out.
For example, on this video:
https://vimeo.com/358768871
Don't you find something like `https://vod-adaptive-ak.vimeocdn.com/exp=1760299020~acl=XXX/v2/playlist/av/primary/prot/cXNyPTE/playlist.json` » in the network tab ? (You shouldn't event need to start the video, just load the page).
I just tried it and it worked.