skylot/jadx · warning · JadxRuntimeException

Can't decode value:

Error message

Can't decode value: 

What it means

Thrown by AnnotationGen.encodeValue() as the default branch of the switch on encodedValue.getType(). All known EncodedValueType values (ENCODED_NULL through ENCODED_ANNOTATION) are handled; reaching the default means an unrecognized encoded value type was encountered. This indicates either a corrupted DEX annotation or a future DEX format extension.

Source

Thrown at jadx-core/src/main/java/jadx/core/codegen/AnnotationGen.java:219

				break;
			case ENCODED_ARRAY:
				code.add('{');
				Iterator<?> it = ((Iterable<?>) value).iterator();
				while (it.hasNext()) {
					EncodedValue v = (EncodedValue) it.next();
					encodeValue(cls.root(), code, v);
					if (it.hasNext()) {
						code.add(", ");
					}
				}
				code.add('}');
				break;
			case ENCODED_ANNOTATION:
				formatAnnotation(code, (IAnnotation) value);
				break;

			default:
				throw new JadxRuntimeException("Can't decode value: " + encodedValue.getType() + " (" + encodedValue + ')');
		}
	}

	private StringUtils getStringUtils() {
		return cls.root().getStringUtils();
	}
}

View on GitHub (pinned to e738a26571)

Solutions

1. Update jadx to the latest version — newer releases may handle additional encoded value types.
2. Report the offending DEX file as a test case to the jadx issue tracker.
3. Exclude the affected class or use fallback decompilation mode to skip annotation generation.

try {
    annotationGen.encodeValue(root, code, encodedValue);
} catch (JadxRuntimeException e) {
    if (e.getMessage().startsWith("Can't decode value")) {
        // Fallback: emit the raw encoded value as a comment
        code.add("/* unsupported annotation value type: " + encodedValue.getType() + " */");
        logger.warn("Unsupported annotation encoded value type", e);
    } else {
        throw e;
    }
}

When it happens

Trigger: Processing a DEX file whose annotation contains an encoded value type constant not in the known set. Corrupted annotation data or a novel obfuscation technique that produces non-standard encoded value tags.

Common situations: Heavily obfuscated APKs with modified DEX structures. DEX files produced by non-standard compilers or post-processing tools.

Related errors

• Unexpected field type class:
• Failed to generate 'invoke-custom' instruction:
• Input class not found: {}
• Failed to generate code for class: ${cls.getFullName()}
• Method generation error

AI-assisted analysis of skylot/jadx@e738a26571 (2026-08-14). Data as JSON: /api/errors/13fa44acde79519b. Report an issue: GitHub.