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This article describes common issues that may occur while using MDN, and ways to remedy them.

Unable to save a page

Symptom
You try to save some change that you have made, and you get an error message indicating that your change couldn't be saved.
Cause
Your change has been caught in MDN's spam trap. As we all know, they make mistakes sometimes.
Remedy
Save a copy of your revision and send an email to the MDN site administrators, as instructed in the error message. One of the admins will verify that it is, in fact, a legitimate change, then train the spam filter not to block edits like yours, and add you to a whitelist so that you don't encounter this problem in the future.

Your published changes do not appear on the page

Symptom
You make some changes to an article and click Publish; the changes that you just made are not reflected in the normal view of the page.
Cause
The page content is cached on the server, and has not been refreshed since the page was changed.
Remedy
Force a refresh of the page in your browser (for example, Shift+Reload). You might see the updated content, or you might see a message indicating that an update to the page is being processed. In the second case, wait a few minutes and do a regular refresh to see if the page has been updated.

Macro-generated content is out of date

Symptom
You see a page that contains content generated by a macro. You know that this macro has been updated and put into production, but the page is showing outdated values.
Cause
The macro output is cached, and has not been refreshed since the macro was updated. At this time, changes made to macros' code do not automatically cause pages that use the macros to be updated.
Remedy
Force a refresh of the page in your browser (for example, Shift+Reload). You might see the updated output, or you might see a message indicating that an update to the page is being processed. In the second case, wait a few minutes and do a regular refresh to see if the page has been updated.

Scripting error on a page

Symptom
You see a scary red box like this on a page:
There was a scripting error on this page. While it is being addressed by site editors, you can view partial content below. More information about this error
Cause
This is caused by a KumaScript error in a macro on the page. This issue is less common in production now that macros are stored on Github and go through a review and testing process before being put into production. You might see it if you modify a macro call or its arguments in a way that breaks the macros. You might also see it  if you are editing macros on a local build of the MDN platform.
Remedy
If you modified a macro call, you can check the name and parameters of the macro against the KumaScript Github repo. If you are in the midst of modifying the macro in question, Troubleshooting KumaScript errors may be helpful.

Scripting error while previewing a page

Symptom
You are editing a page, and click the Preview button. The preview of the page contains a scripting error message (as shown in the previous section).
Cause
Either there was an existing scripting error in the page you were editing, or you have introduced an error, possibly by changing arguments to a macro.
Remedy

Be assured that as long as you have not modified or added any macros or templates in the page, you can safely ignore this error; you can expect it to go away when the edited page is finally saved and viewed normally again (unless the error was already there in the normal view).

If you are still unsure whether you introduced the error, then you can open a copy of the same page in a new window (so you have the last saved version of the page), enter Edit mode, and immediately click Preview. If any errors occur now, you can be confident that you did not cause them, and that they will likely disappear as previously described.

As for your changes, if these new errors are the same as the old errors from the old window, then close the new window and continue working in the old one. However, if they are different errors, then you indeed might have damaged something in the old window, so just start carefully copying your changes to the new window, and click Preview after each copy. If the old errors suddenly appear here too, then your last changes have likely caused them, and you should carefully examine that work. Finally, as a side benefit, if you click Preview frequently and always leave that Preview window open, you will have a quick but unsaved copy of most of your changes in case the editor fails or somehow loses your work (as may happen when trying to use Discard).

Document Tags and Contributors

 Contributors to this page: Sheppy, jswisher
 Last updated by: Sheppy,