[Bug]: Subtitles conversion fails

[ProbaTest1122]

What happened?

Run into a strange situation where the output will complain about an error in capture download and conversion to .srt.

At the end of the course download output folders contain the correct .vtt files and strangely .srt files with 0 bytes.

Expected Result

Output folders should only contain the .srt captions

Branch

master/main

What operating systems are you seeing the problem on?

Linux/Unix

Relevant log output

[09:11:37] [udemy-downloader] [parse_new:1443] INFO:   > Processing lecture 1 of 15
[09:11:37] [udemy-downloader] [process_lecture:1361] INFO:       > Lecture doesn't have DRM, attempting to download...
[09:11:37] [udemy-downloader] [process_lecture:1370] INFO:       ====== Selected quality: hls 1080
[09:11:37] [udemy-downloader] [process_lecture:1399] ERROR: >        Error downloading lecture
Traceback (most recent call last):
  File "/home/kali/Downloads/udemy-downloader/main.py", line 1387, in process_lecture
    log_subprocess_output("YTDLP-STDOUT", process.stdout)
  File "/home/kali/Downloads/udemy-downloader/main.py", line 55, in log_subprocess_output
    for line in iter(pipe.readline, b''):  # b'\n'-separated lines
AttributeError: 'NoneType' object has no attribute 'readline'
[09:11:37] [udemy-downloader] [parse_new:1474] INFO: Processing 1 caption(s)...
[09:11:37] [udemy-downloader] [process_caption:1306] INFO:     >  Downloading caption: '001 Introduction_en.vtt'
[09:11:37] [udemy-downloader] [process_caption:1318] ERROR:     > Error downloading caption: 'NoneType' object has no attribute 'readline'. Will retry 3 more times.
[09:11:37] [udemy-downloader] [process_caption:1306] INFO:     >  Downloading caption: '001 Introduction_en.vtt'
[09:11:37] [udemy-downloader] [process_caption:1318] ERROR:     > Error downloading caption: 'NoneType' object has no attribute 'readline'. Will retry 2 more times.
[09:11:37] [udemy-downloader] [process_caption:1306] INFO:     >  Downloading caption: '001 Introduction_en.vtt'
[09:11:37] [udemy-downloader] [process_caption:1318] ERROR:     > Error downloading caption: 'NoneType' object has no attribute 'readline'. Will retry 1 more times.
[09:11:37] [udemy-downloader] [process_caption:1306] INFO:     >  Downloading caption: '001 Introduction_en.vtt'

02/14 21:11:37 [NOTICE] Downloading 1 item(s)
[09:11:37] [udemy-downloader] [process_caption:1313] ERROR:     > Error downloading caption: 'NoneType' object has no attribute 'readline'. Exceeded retries, skipping.

Other information

No response