Malformed signature for license builder uid – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when the signature for the Elasticsearch license is not correctly formed. This could be due to an incorrect license UID or a problem with the license file itself. To resolve this issue, you can try regenerating a new license file from the Elasticsearch service, ensuring the UID is correct. Alternatively, you can check the integrity of the license file, ensuring it hasn’t been tampered with or corrupted. If the problem persists, you may need to contact Elasticsearch support for further assistance.

This guide will help you check for common problems that cause the log ” malformed signature for license [” + builder.uid + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, license.

Log Context

Log “malformed signature for license [” + builder.uid + “]” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 try {
 byte[] signatureBytes = Base64.getDecoder().decode(builder.signature);
 ByteBuffer byteBuffer = ByteBuffer.wrap(signatureBytes);
 version = byteBuffer.getInt();
 } catch (Exception e) {
 throw new ElasticsearchParseException("malformed signature for license [" + builder.uid + "]"; e);
 // we take the absolute version; because negative versions
 // mean that the license was generated by the cluster (see TrialLicense)
 // and positive version means that the license was signed
 if (version < 0) {