Question
Shuurgan
CN
Last activity: 12 Aug 2025 20:30 EDT
Error occurred while using a web component.
Hello, I'm encountering an error message when using a web component. The Japanese text in the image means: "Cannot access a discarded object. Object name: VirtualHtmlTableElementTarget."
The web component is a table. Could you please tell me how to resolve this issue?
Thank you.
BAO
HCA Healthcare
US
This error means your automation is trying to use a table element that the browser already destroyed and replaced, usually after a page refresh, navigation, or a reactive re-render. Fix it by never caching cell or row proxies and always re-locating the table right before you use it. Add a WaitForCreate (or check control.IsCreated) on the table and any child elements before every interaction, with a sensible timeout and a small retry loop. Rebind after any click that can change the DOM: navigate/click → wait for document complete → wait for table created → then read or click. Use the control’s Created/Destroyed (or OnCreated/OnDestroyed) events to set a boolean flag like tableReady and gate your logic on that flag. If your match rules use volatile attributes (random IDs, dynamic indexes), tighten them: prefer stable attributes, parent/ancestor relationships, and text patterns; avoid relying on nth-child or transient classes. If you’re using an index to reach rows, re-query the Rows collection each time instead of storing a reference. After sort/filter actions, refresh your match (or re-find) before touching the table. Guard every use with try/catch and log when IsCreated is false to spot race conditions. If the page uses infinite scroll or virtualization, scroll the table into view first so the target row exists. Avoid long parallel threads touching the same control; serialize table access via a queue or a single “table worker” automation. Confirm the adapter event order: wait for DocumentCompleted (or a reliable ready signal) rather than a fixed sleep. Upgrade to the latest 19.1 Runtime/Studio build and apply hotfixes for the Edge/Chromium adapter, since older builds had disposed-object issues on fast refreshes. As a last resort, replace direct cell clicks with higher-level actions (search then invoke a stable link in the same row) to reduce DOM churn sensitivity. Test by throttling network speed to reproduce timing and validate your waits. This pattern eliminates “Cannot access a discarded object: VirtualHtmlTableElementTarget” because you only touch elements that are freshly created and currently alive.
Pegasystems Inc.
US
@BAOX17175074This is interesting. I would need to look at your RuntimeLog to have more information. Can you share a screenshot of the automation and the step where this is happening? I see this most when you are iterating a clone collection before it has completed matching. You might try adding a pause (start with a long one to be certain) before this step and see if this message goes away. If it does, it is likely because you are waiting on a parent of a clone rather than the clones themselves. There's really no way to wait specifically for all clones to be matched since they could technically be added to your page at any time. If they are all added at one time however, you can use a trick that has proved successful for me. I use a For Loop (in 19.1) or a while loop in 22.1 or R25 to check the count of the clone collection and store it. Pause for a brief period and then check the clone collection again and see if it is different than it was before. If it is, record the new count and return to the loop. If the count is the same, then you know that matching of all of the clones available has completed.
You can look in your RuntimeLog and see if the clones are still matching after this exception to get evidence for my theory. Make sure you do this without breakpoints though to be sure.