Wrote a WP Cron Plugin and it triggers a fatal error upon activation

Disabled all plugins and re-enabled only the necessary ones for this plugin to run correctly (a custom-post-types & custom-taxonomies plugin). Re-activated the plugin and got the error message but with a detail that the line 128 had a semicolon in it. As this was a function being called to get the ID of the element in an array, it should have been followed by a , rather than a ;. Changed this, and activated the plugin successfully.

Moral of the story: Try deactivating plugins that may be interfering with error display & if the error display appears clearly.