As of Adobe Experience Manager (CQ) 5.5 and later, changes to the metadata of an asset are written back to the original binary as part of its XMP metadata. Write-back is enabled by default, but it is not supported in all operating systems. In those operating systems, Adobe recommends that you disable the write-back to prevent DAM workflow failures.
Check here to see if your operating system is supported.
- Click the + sign for Supported Formats and leave it blank (Don't enter any mimetype) at 
- Remove all the mime types configured for writeback at  except the one added earlier.
- Once you update the configuration, restart the system for changes to be effective.
Do not disable the DAM XMP Write-back by removing the Launcher configuration via the Workflow Console. Doing so disables other features such as thumbnail generation.
Note for 64-bit Linux users :
The AEM Metadata write-back workflow uses the XMPWorker Linux fragment which is a 32-bit native executable application that AEM runs on the OS shell.
If you are using 64-bit Linux, then it is possible that you do not have the dynamic runtimes installed to execute the 32-bit library. This other article provides steps to install the required 32-bit libraries in Redhat Enterprise Linux or CentOS.