This page can't be displayed. Try reloading the page, or contact your administrator.

This is the most generic error message Lightning can produce. Salesforce shows it whenever something at the page level catches fire and the runtime doesn't have a more specific message. The "try reloading" suggestion is misleading — reloading rarely fixes anything substantive.

The diagnostic flow

Step 1: open the browser console

Press F12 (or Cmd-Opt-I on Mac), go to the Console tab. Reload the page. You'll see one or more red error lines. Read those, not the user-facing message. Usually one of:

• TypeError: Cannot read properties of undefined ... — see the LWC version
• Action failed: c:something$controller$action [...] — see the Aura version
• Refused to connect to ... CSP violation — see the CSP version
• Insufficient privileges on a sub-component
• Component cannot be created: <component name> — usually a missing dependency

Step 2: identify which component failed

The browser stack trace names the component. Open Setup → Lightning App Builder, find the page, and look for that component on the layout. Either remove it (to confirm it's the culprit) or fix the underlying issue.

Step 3: check user permissions for that component

Some components require specific permission sets to render. If a user lacking that permission lands on the page, the component throws and the whole page error-screens. Either:

• Add a lwc:if condition in the parent component that hides the gated child for users without the permission
• Use Component Visibility rules in Lightning App Builder to hide the component for unsupported user types

When the cause is component count

A Lightning record page has hard limits:

• 25 custom components in any record page (this is per page, not per org)
• Roughly 100 standard components
• Total component count + complexity has a memory budget; deeply nested compositions can hit it

If your page has 30 LWCs and you're seeing the generic error, that's a candidate cause. Lightning App Builder shows component count in its sidebar — if you're near the limit, prune.

When everyone sees it but only on one record

The component might be rendering different content based on the record. If Account A works and Account B doesn't, your code is reading something on Account B that's null/undefined or that breaks an assumption. Add the record's IDs to the URL and try in DevTools to see the failing case more cleanly.

A subtle cause: a deleted dependency

If your component imported MyService.cls and someone deleted that class without updating the LWC, the LWC compiles (the import is resolved at deploy time) but throws at runtime. The error doesn't say "missing dependency" — it says the generic page error.

Fix: search the org for references and ensure all dependencies still exist.

A workaround that isn't a fix

Disabling Lightning Locker Service ("Locker") is sometimes suggested. Don't. Locker exists to sandbox component code from cross-component access; turning it off creates security holes. If your component needs to do something Locker blocks, refactor; don't disable.