XML Language Server Crashes Due to an Out Of Memory Error

[itchozyn]

WHen I start VSCode after the latest update, XML Server crashes. Full Output text from "XML Support":

[Info - 10:40:14 AM] Oct 10, 2025 10:40:14 org.eclipse.lemminx.XMLLanguageServer initialize()
Message: Initializing XML Language server
LemMinX Server info:

• Version : 0.31.0
• Java : C:\Program Files\Java\jdk-21
• VM Version : 21.0.8
• Git de7f529 - [maven-release-plugin] prepare release 0.31.0
  [Info - 10:40:37 AM] Oct 10, 2025 10:40:36 org.eclipse.lemminx.extensions.contentmodel.uriresolver.XMLCatalogResolverExtension setCatalogs()
  Message: Adding XML catalog 'c:\Users<snipped>.vscode\extensions\salesforce.salesforcedx-vscode-core-64.17.2\resources\metadata-catalog.xml' with expand system id 'file:///c:/Users//.vscode/extensions/salesforce.salesforcedx-vscode-core-64.17.2/resources/metadata-catalog.xml' and root URI 'file:///c%3A/Users//Documents/newITBatch/'.
  [Info - 10:40:37 AM] Oct 10, 2025 10:40:36 org.eclipse.lemminx.extensions.contentmodel.uriresolver.XMLCatalogResolverExtension setCatalogs()
  Message: Adding XML catalog 'c:\Users<snipped>.vscode\extensions\salesforce.salesforcedx-vscode-lwc-64.17.2\resources\static\js-meta-home.xml' with expand system id 'file:///c:/Users//.vscode/extensions/salesforce.salesforcedx-vscode-lwc-64.17.2/resources/static/js-meta-home.xml' and root URI 'file:///c%3A/Users//Documents/newITBatch/'.
  [Error - 10:40:40 AM] Connection to server got closed. Server will not be restarted.

VSCode About:
Version: 1.105.0 (user setup)
Commit: 03c265b1adee71ac88f833e065f7bb956b60550a
Date: 2025-10-08T14:09:35.891Z
Electron: 37.6.0
ElectronBuildId: 12502201
Chromium: 138.0.7204.251
Node.js: 22.19.0
V8: 13.8.258.32-electron.0
OS: Windows_NT arm64 10.0.26100

[datho7561]

Is this happening after the latest update of VS Code? We haven't released a new version of vscode-xml in a while.

There's nothing in the logs here that can help us to figure out when wrong, unfortunately.

Were you trying to edit a large XML file? Did you try changing the memory allocated to the extension through modifying the setting xml.server.vmargs? (eg. adding -Xmx1G will increase the memory allow to be used to 1 gigabyte).

It could be specific to running Windows arm64, I don't think that we have access to a Windows arm64 machine to test it, unfortunately.

[itchozyn]

Yes, it started after the last update. I am only developing for Salesforce in Apex right now. Each Salesforce file has an associated XML file with its metadata settings. But none of them are very large and I usually do not edit them directly. Perhaps VSCode does make changes to them when I update the files, but I don't know.

I specified 512MB for the xml.server.vmargs, but it still crashed. I then switched to the binary server and it works.

I would agree that this new ARM processor architecture has issues with otherwise stable apps.

[fgarciachipi]

I'm having the same problem in a Apple M1 ARM processor. Increasing memory didn't fixed it.

[angelozerr]

Even with binary mode?

[readeral]

@itchozyn I've noticed this issue today running on Apple M1 pro so it's not specific to windows. but I do think it's related to Salesforce as I'm also a salesforce dev.

The XML catalog metadata-catalog.xml pulls in salesforce_metadata_api_clean.xsd which in turn pulls in salesforce_metadata_api_common.xsd which is ~38000 lines long, but it's still only 2.6MB.

This comes from a feature developed a few months ago to leverage the vscode-xml extension more fully: forcedotcom/salesforcedx-vscode#6576
Released on October 3.

They then fixed an issue with the feature on November 6. The salesforce_metadata_api_clean.xsd didn't have a closing tag, so I presume didn't load the common.xsd (forcedotcom/salesforcedx-vscode#6622)

I'm sure I've had my extensions up to date since Nov 6, but perhaps that fix for the new feature that actually pulled in the large xsd definition may have something to do with it?

[angelozerr]

I am improving memory, could you give me a link with the XML which causes the problem please.