Error: Invalid character: "The \";\" character is not valid" (semicolons in HCL)

Not specified by the original author.

TL;DR

HCL does not use semicolons. If you wrote variable "x" { type = string; default = "y" } on one line, Terraform rejects the ;. Put each argument on its own line and the error goes away.

The error

Error: Invalid character
The ";" character is not valid. Use newlines to separate arguments and blocks

Steps to fix

1. Open the file and line the error names. Look for ; separating arguments on one line.

   • Expected: you find the single-line block with semicolons.

2. Expand it to one argument per line:

   variable "common_tags" {
     type    = map(string)
     default = {}
   }

   • Expected: no semicolons remain in the block.

3. Run terraform fmt to normalize the file, then terraform validate.

   • Expected: Success! The configuration is valid.

When to use this

• terraform validate/plan fails with Invalid character pointing at ;, backticks pasted from markdown, or other stray characters, right after writing or pasting config.

When NOT to use this

• Missing newline after argument is the sibling syntax error (different message). If the invalid character is invisible, suspect smart quotes or zero-width characters from copy-paste and retype the line.

Compatibility

• All Terraform versions; HCL syntax rules are stable.

Root cause

HCL's native syntax separates block arguments with newlines, not semicolons. People coming from JSON, Python, or C-style languages write one-line blocks with ; separators out of habit, and the HCL parser rejects the character outright.

Edge cases

• Backticks accidentally pasted from markdown code fences produce the same error naming the backtick character; rewrite the file from the terminal to be safe.
• $var.name without braces (shell-style) is a different error (Invalid character naming $); use ${var.name} inside quotes.
• terraform fmt fixes indentation but does not remove semicolons; you must edit them out.

A real project troubleshooting log records hitting this 3+ times across modules: "Error: Invalid character. The \";\" character is not valid. Use newlines to separate arguments and blocks". The root cause was single-line variable blocks like variable "common_tags" { type = map(string); default = {} }, which HCL forbids. The fix was to always expand variable blocks to multi-line format, with the rule "never put semicolons in HCL." A separate Medium walkthrough shows the same error from backticks accidentally pasted from markdown into a .tf file.