This PHP fatal error indicates your website process exceeded its maximum RAM allocation. Every PHP script has a memory limit set at the server or application level. When a script requires more memory than the limit allowed, the process terminates immediately to prevent server instability.
The issue often stems from heavy scripts or large data sets. It occurs during resource heavy operations like image processing, database migrations, or running multiple complex plugins simultaneously. The error message explicitly identifies the file and line number where the memory ceiling was hit.