When a WordPress site on an OpenLiteSpeed (OLS) server fails while uploading or updating a plugin/theme, the issue may be related to incorrect ownership of OpenLiteSpeed temporary files.
This guide explains how to identify the issue and apply the known fix.
Symptoms #
A customer may report one or more of the following:
- Plugin upload fails
- Plugin update fails
- Theme upload fails
- Theme update fails
- WordPress shows a 500 Internal Server Error
- The issue happens during upload/update actions only
- The site is hosted on an OpenLiteSpeed / OLS stack server
Example customer message: #
I cannot update the theme. It is showing a 500 error on your server
Affected Stack #
This issue is related to servers using the OpenLiteSpeed (OLS) stack.
It does not usually happen on NGINX stack servers.
In customer-friendly language:
Your server is using the OpenLiteSpeed stack. This issue is related to OpenLiteSpeed temporary file handling and is not related to Redis or cache settings.
Error to Look For #
Open the server logs in xCloud:
Server → Logs #
Or use the direct server logs URL:
https://app.xcloud.host/server/{server_id}/logsLook for this error:
Failed to obtain or reinitialize VMemBuf.
Example: #
2026-05-13 06:27:02.750619 [ERROR] [269567] [192.128.217.123:13925:H2-1]
Failed to obtain or reinitialize VMemBuf.
If this error appears while the customer is uploading or updating a plugin/theme, apply the fix below.
Likely Cause #
OpenLiteSpeed uses temporary swap/report files under:
/tmp/lshttpd/
In some cases, these files or folders may have incorrect ownership. When OpenLiteSpeed cannot write to or reinitialize these temporary buffers properly, WordPress actions such as plugin/theme upload or update can fail with a 500 error.
The fix is to restore ownership to the correct server user:
xcloud:xcloud
Fix #
SSH into the server or use the xCloud Command Runner.
Run: #
chown -R xcloud:xcloud /tmp/lshttpd/swap
chown -R xcloud:xcloud /tmp/lshttpd/.rtreport*Using xCloud Command Runner #
If you are using the xCloud dashboard:
1. Open the xCloud dashboard.
2. Go to Servers.
3. Select the affected server.
4. Open Command Runner.
5. Run the following commands:
chown -R xcloud:xcloud /tmp/lshttpd/swap
chown -R xcloud:xcloud /tmp/lshttpd/.rtreport*
6. Wait for the command to finish.
7. Ask the customer to test the plugin/theme upload or update again.
Verification #
After applying the fix, ask the customer to retry the same action:
– Upload the plugin again
If successful, the issue is resolved.
Also, check the server logs again and confirm that the same error is no longer appearing during the upload/update attempt:
Failed to obtain or reinitialize VMemBuf.
