skylot/jadx · error · JadxRuntimeException

Unknown variable: '{}' in template: {}

Error message

Unknown variable: '{}' in template: {}

What it means

Thrown as JadxRuntimeException by TemplateFile.processVar() when values.get(varName) returns null, meaning the template references a variable that was never registered via TemplateFile.add(name, value). The template engine requires every '{{variable}}' placeholder to have a corresponding add() call before build()/save(). The error includes both the variable name and the template file name.

Source

Thrown at jadx-core/src/main/java/jadx/core/export/TemplateFile.java:159

					case START:
						parser.state = State.NONE;
						return "{" + ch;

					case END:
						throw new JadxRuntimeException("Expected variable end: '" + parser.curVariable
								+ "' (missing second '}')");
				}
				break;
		}
		parser.skip = false;
		return null;
	}

	private String processVar(String varName, boolean rawValue) {
		String str = values.get(varName);
		if (str == null) {
			throw new JadxRuntimeException("Unknown variable: '" + varName
					+ "' in template: " + templateName);
		}
		if (!rawValue) {
			Function<String, String> sanitizer = valueSanitizer;
			if (sanitizer != null) {
				return sanitizer.apply(str);
			}
		}
		return str;
	}
}

View on GitHub (pinned to e738a26571)

Solutions

1. Check the template file (named in the error message) for all '{{...}}' placeholders and ensure each has a matching tmpl.add() call.
2. Verify variable name spelling and case match exactly between template and code.
3. If using stock jadx templates, report the bug with the template name and variable name from the error.
4. For custom templates, add a tmpl.add(varName, value) for every referenced variable, or remove unused placeholders from the template.

Example fix

// before — template has {{version}} but code does not add it
TemplateFile tmpl = TemplateFile.fromResources("/export/build.tmpl");
tmpl.add("projectName", name);
tmpl.save(file); // error: Unknown variable 'version'

// after — add all referenced variables
TemplateFile tmpl = TemplateFile.fromResources("/export/build.tmpl");
tmpl.add("projectName", name);
tmpl.add("version", version);
tmpl.save(file);

// Before rendering, collect all variable names from the template
// and ensure each is registered via add()
Set<String> requiredVars = extractTemplateVariables(templateContent);
for (String var : requiredVars) {
    if (!values.containsKey(var)) {
        throw new IllegalStateException("Missing template variable: " + var);
    }
}

try {
    tmpl.save(outFile);
} catch (JadxRuntimeException e) {
    if (e.getMessage().contains("Unknown variable")) {
        LOG.error("Template variable not provided: {}", e.getMessage());
        // Add the missing variable or fix the template
    } else {
        throw e;
    }
}

When it happens

Trigger: A template file contains '{{projectName}}' but the calling code never calls tmpl.add("projectName", value). This occurs when a template is updated to reference a new variable but the generator code is not updated to supply it, or when a variable name has a typo mismatch between template and code.

Common situations: Internal jadx bug where a template and its generator code are out of sync. Custom export templates referencing variables the generator does not provide. Case-sensitivity or whitespace issues in variable names (note: variable names are collected character-by-character, so embedded whitespace matters).

Related errors

• Duplicate plugin id: {}, class {}
• Failed to generate gradle files
• Resource not found: {}
• Template already processed
• Expected variable end: '{}' (missing second '}')

AI-assisted analysis of skylot/jadx@e738a26571 (2026-08-14). Data as JSON: /api/errors/b241ddea20d33a37. Report an issue: GitHub.