Situation
You’ve created your custom elements in SharePoint and everything is flowing along smoothly until you add an out-of-the-box SharePoint web part to a page. When you try to edit this web part, you get a non-helpful error message that cryptically states that “A Web Part you attempted to change is either invalid or has been removed by another user. Refresh page.”. This error appears in the Editor Pane on your SharePoint page (see below).
The error message appears to hint that there’s a concurrency issue and that someone else has modified this page just before you tried to. Unfortunately, there’s no associated correlation ID or any other way to troubleshoot or otherwise resolve the error. Sadly, in most instances, a refresh will not resolve this problem. Something much harder to diagnose is going on behind the scenes. We’ll get to solving the problem, but first some background.
Solution
Have you ever heard the rule that every element in HTML must have a unique ID? Even elements that don’t have a manually defined ID are given one behind the scenes. Your browser, however, will not complain when two elements have the same ID. Also, any call to document.getElementById() will return just the first element that matches the given ID. So if you have an element earlier on your page with the same ID as the web part you’re trying to edit, document.getElementById will return the first element every time.
This is exactly what’s happening here. When you go to edit a Web Part, there’s a POST back to load the editor code, and there’s a large amount of JavaScript that runs on the client to properly open the editor. This JavaScript is failing because it expects to find your web part and instead finds something else that exists earlier in the HTML. That’s why there’s no correlation ID, no error in the logs, and no simple way to troubleshoot.
The question then becomes: what IDs aren’t valid? Fortunately, out-of-the-box SharePoint web parts have a very standard naming scheme for IDs, which are assigned by the SPWebPartManager on the page. These IDs follow the scheme WebPartWPQ followed by a number. So if you’re seeing this error, the first place to check is for the presence of other elements that have the same ID as a web part but shouldn’t. Removing that ID from the offending element on the server should clear up the error. It’s not enough to remove the SPWebPartManager because it will be added back by SharePoint when you save the page.
I am getting that error on a website that they have a custom content editor web part and the OOTB. I am thinking it is either one or the other that is having the problem. How do I identify the ID?
As I said in my post, OOTB web parts have WebPartWPQ as part of their ID. Search the page’s source for the IDs that match this string. You should be able to find the offending IDs pretty easily with this approach.
Same issue. I looked in the page source and found the webpart was assigned WebPartWPQ8, but I don’t see another element in the source with the same id.
If I’m understanding this blog post correctly, I should be, right? Well, assuming it’s the same problem, and not something else.
Nevermind, I found it….was looking at the wrong ID. I’m not really sure what to do with it now though. How do I remove the “offending element on the server”?
How you go about fixing this error depends on the other element that shares the same ID. If it’s just HTML that you’ve added to the page, the fix is as easy as changing or removing the ID for this element. If it’s a custom control or web part, you’ll need to change the ID in the ascx or code behind for the item in question.
Thanks for all your information so far, Andrew. I am working with MarkP on this. What I see is the customer created a custom content editor web part by simply setting the settings in the panel they wanted, they exported, renamed and uploaded it to the web parts list. The issue I see is when I pull the code for the web part, I do not see an assigned ID, so I am assuming since it is using the exact same code as the OOTB, it is generating the conflict. If I just export the web part I do not see an ID to modify as I believe it is pulling from SP. Any thoughts to this?
Curious. It’s not possible to set the ID explicitly from the web part’s dwp/webpart file as you’ve discovered. Have you compared an export of the OOTB web part that you’re unable to edit (provided you can export it) to the customized OOTB web part’s export?
Yes, I compared it and since they used the OOTB to just export, made minor changes (all I can see is they changed to no chrome to display and that is it) then saved it and uploaded it into their library of web parts.
I have no idea why the slightly customized web part would pick up the same ID. If you remove the customized web part does the edit error go away?
If all they have customized is the chrome property, perhaps they could use the OOTB web part and change the chrome setting for the web parts that need it instead of using the customized web part? I realize this doesn’t explicitly solve the problem, but hopefully it will circumvent it. If you continue to have issues after that, then something else is the culprit.
Hi Andrew, well, I believe the issue was that content was copied from the web part itself (the custom no chrome) and then pasted into the content area on the page (thanks Mark for nailing it down) and thus this copied the ID in the “behind the scenes” and thus created some confusion on how SP was looking at the page. Going into the source code of the content area on the page (which is just a part of the page layout) and removing the reference to the webpart ID – the page works fine. 🙁 So while I don’t like that answer, that is what we landed on. I don’t know of any way to clean this up other than deal with the pages that this process occurred on indvidually?
Oh – one question, why would this have not reared its head in SP 2007? That is what I am missing here as this entire issue was migrated over into SP 2010 and that is when things “broke.” I am making an assumption that something in the code of how SP handles the assignment or management of the web part IDs? Maybe a script difference, but that is stretching into areas that I am most certainly not an expert! Any thoughts?
Unfortunately, there’s no quick or easy way to deal with web parts on a page. The most effective way is to attack each page as it appears and modify the web parts accordingly.
As to why this error only occurs in SP2010, it’s because of the JavaScript that exists in SP2010 that doesn’t exist in SP2007. Editing web parts in SP2010 is all done through JavaScript and POSTbacks, while in SP2007 it’s done through POSTbacks and code behind. As far as I am aware, the assignment of web part IDs hasn’t changed between 2007 and 2010.
I’ve been having similar issues as outline in part 12. Is there a way to instant message back and forth to solve this issue?
Rachel, this situation is almost always related to Web Parts with overlapping IDs. Once your page is open, search for the web part that’s causing the issue and find the ID (it will have WebPartWPQ in it) and then search for that ID. Each Web Part’s ID should only appear once on the page or you will run into errors.