# SyteLine and Mongoose Event System Troubleshooting Checklist > Source: https://netray.co/tools/syteline-event-system-troubleshooting-checklist > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Checks for event handlers in SyteLine 9 and CSI 10 that do not fire, fire twice or hang, from event name and flags to runtime services and action outcomes. ## Category developer ## Erp Infor SyteLine ## Audience - Mongoose developer - ERP administrator - SyteLine support analyst ## Tool **Kind:** checklist **Groups:** #### Definition **Items:** **Text:** Handler is on the right event: On events (for example IdoOnItemInsert) run before the change, Post events (IdoPostItemInsert) after it **Critical:** true Applies-to IDO or object filter matches the IDO the form actually uses, not a similarly named one Condition expression evaluated by hand against a real record returns true Handler is active and not marked obsolete **Text:** Handler sequence checked against all other handlers on the same event, including Infor-shipped handlers that may finish or fail first **Critical:** true #### Execution mode **Items:** Synchronous or asynchronous setting matches the design: synchronous handlers block the user, asynchronous ones run later from the queue **Text:** Handlers using Prompt or Wait actions are set to suspend, and the suspension stages are understood (validate, roll back, queue, commit) **Critical:** true Transactional setting checked: a failing handler rolls back all data in a transactional event; asynchronous handlers are outside that transaction Ignore Failure check box reviewed: with it set the handler is treated as successful unless an illegal operation is attempted, yet Event Handler Status still shows Failure #### Runtime **Items:** **Text:** Framework event service running for the configuration so asynchronous and suspended handlers are processed **Critical:** true Event Status form shows the event, its state and the Any Handlers Failed indicator Event Handler Status shows the result message, Times Failed on the Actions tab, Last Activity Date on the Handlers tab and variable values on the Variables tab **Text:** Event global constants hold the right values for this environment (no production email addresses in test, no test URLs in production) **Critical:** true Retry used only for handlers that are retryable; illegal operations cannot be retried #### Actions **Items:** Fail and Finish outcomes placed deliberately: Fail stops the event with an error, Finish ends the handler successfully Call IDO Method parameters in the method's order, with output parameters marked as output Set Values expressions read event variables with V() and reference parameters and event global constants with the functions listed in your release's expression help Notify recipients exist as users with email addresses, and email delivery from the server works Load IDO Row and other read actions return exactly one row where the next action assumes one #### Testing **Items:** **Text:** Reproduce with one user in a test environment and a single record **Critical:** true Read the Event Status and Event Handler Status message for that event instance LogMonitor open during the test to see IDO and event messages in order Test the failure path as well as the success path Disable the handler and confirm the original problem disappears before changing other handlers Retest after every Infor update, since shipped handlers on the same event can change **Scoring Note:** Most event problems come from three places: the wrong event name (On versus Post), handler sequence against Infor-shipped handlers, and asynchronous or suspended handlers with no service to run them. Check those critical items before rewriting any action. ## Content **Intro:** The Mongoose application event system in SyteLine 9 and CSI 10 runs handlers when framework or custom events fire. This checklist finds why a handler does not fire, fires twice, or leaves the user waiting. **Sections:** #### How to use it **Body:** Pick one failing event and one test record. Walk Definition first, because most handlers that never fire are attached to the wrong event or filtered to the wrong IDO. Then check Execution mode and Runtime, which explain handlers that hang or run late. Leave Actions for last: rewriting actions before you know the handler actually runs wastes the most time. Export the ticked list with screenshots of Event Status for the ticket. #### Where this lives in Mongoose **Body:** Events, handlers and actions are maintained on the Events and Event Handlers forms. Framework events such as IdoOnItemInsert, IdoPostItemUpdate, SessionOnLogin, TaskPostPerform and BodOnReceive are built in; you add handlers to them but cannot add your own triggers for framework events. Run results appear on Event Status and Event Handler Status. Asynchronous and suspended handlers are processed from the event queue by the framework event service on the server. **Bullets:** - On events: before the change, can stop it - Post events: after the change has happened - Event Status: per event instance, Any Handlers Failed - Event Handler Status: result, Times Failed, variables #### Worked example **Body:** A handler meant to email purchasing when a PO line is inserted sends two emails. Event Status shows two instances. The handler was attached to both IdoOnItemInsert and IdoPostItemInsert during testing and both stayed active. Removing the On handler fixes the duplicate. Another handler never fires in production: its condition reads an event global constant that holds the test site code, so the condition is false for every production record. #### Version differences and gotchas **Body:** Flag labels and tab names can differ slightly between SyteLine 9 and CSI 10 builds, so confirm them in your release help. Suspension runs synchronous handlers once in a validating pass that rolls back, then queues the commit, which surprises developers who log side effects in the first pass. Ignore Failure hides failures from the user but not from Event Handler Status. Infor updates can add shipped handlers to the same events you use. **Cta:** If you want an assistant on your own servers that explains which handlers run on an event and why one failed, we can build that over your SyteLine metadata. **Faq:** #### What is Infor Mongoose? **Answer:** Mongoose is the application framework under SyteLine and CSI. It supplies IDOs, WinStudio forms, the application event system, TaskMan background processing and the IDO request service. The event system lets administrators react to framework events such as IDO inserts, logins, tasks and inbound BODs with handlers and actions, mostly without compiled code. #### What is the difference between IdoOnItemInsert and IdoPostItemInsert? **Answer:** IdoOnItemInsert fires while an IDO item is being inserted, so a handler can validate and stop the insert with a Fail action. IdoPostItemInsert fires after the item has been inserted, which suits notifications and follow-on updates. Attaching the same handler to both causes duplicate processing. #### Why does my asynchronous event handler never run? **Answer:** Asynchronous and suspended handlers are queued and processed by the framework event service. If that service is stopped or not configured for the database, handlers wait indefinitely. Check the service on the server, then Event Status for the instance state, then the handler's condition and global constants. #### Where is the Infor Mongoose user guide? **Answer:** Infor publishes Mongoose and SyteLine help on docs.infor.com, including the application event system guide covering events, handlers, actions, synchronicity, transactions, suspension and retrying. Use the help for your exact release, because form labels and supported features differ between SyteLine 9, CSI 10 and later Mongoose versions. ## Search terms infor mongoose user guide, infor mongoose application, infor mongoose guide, what is infor mongoose, syteline event handler, mongoose application event system, syteline event status --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json