How to fix corrupted code in header

Shopify is flagging a problem connected to header.liquid

  • In some editor views, the file appears corrupted or filled with NULL content

  • The normal file length for header.liquid appears to be around 500 to 600 lines

  • But when viewed in VS Code or through other attempts, I have seen line counts in the range of 17,000 to 19,000 lines, which makes no sense to me

  • This makes me suspect file corruption, encoding damage, or hidden invalid content rather than a simple visual artifact

What I need help determining:

  • How can I confirm whether sections/header.liquid is actually corrupted?

  • Could this be caused by bad encoding, binary corruption, or hidden invalid characters inside the file?

  • Is there a reliable way to compare the live Shopify file against a clean theme copy and identify exactly where the corruption begins?

  • If the file is corrupted, what is the safest recovery method?

  • Would restoring only header.liquid from a clean backup be enough, or could related files also be involved?

  • Has anyone seen a Shopify file show a normal size in one place but an absurd line count in VS Code because of corruption or formatting damage?

Important note:

I am not looking for a CSS patch that merely hides the word “Null.” I need to find the root cause and properly repair the file.

Any guidance on how to diagnose this accurately would be greatly appreciated.

:::

Here’s a shorter version too, in case you want something more direct:

:::writing{variant=“standard” id=“48262”}

I need help with a Shopify “Null” issue that does not seem to be solved by the usual CSS masking advice.

In my case, the problem appears tied to sections/header.liquid, not just a visual artifact. My assets/base.css had many errors before, and those were fixed, but the Null issue remains connected to the header file.

What is strange:

  • header.liquid should be about 500 to 600 lines

  • In other views, especially VS Code, I have seen it appear as 17,000 to 19,000 lines

  • In some cases it looks corrupted or filled with NULL content

Because of that, I suspect file corruption, encoding problems, or hidden invalid characters.

Can someone tell me:

  • how to verify whether header.liquid is corrupted,

  • how to compare it properly with a clean copy,

  • and what the safest recovery method would be?

I am not looking for a CSS cover-up. I want to fix the actual source

Can you share your site url so that I can take a look into it.

myshopify.alien-contact.com