由于Internet Explorer 5与Angular 11不兼容，因此最好的解决方法是建议用户升级他们的浏览器。如果必须支持IE 5，则需要使用polyfills来实现兼容性。以下是一个例子，将polyfills添加到polyfills.ts文件中，以便支持IE 5：

/** IE11 requires the following for NgClass support on SVG elements */
import 'classlist.js';  // Run `npm install --save classlist.js`.

/**
 * Required to support Web Animations `@angular/platform-browser/animations`.
 * Needed for: All but Chrome, Firefox and Opera. https://caniuse.com/#feat=web-animation
 **/
import 'web-animations-js';  // Run `npm install --save web-animations-js`.

/**
 * By default, zone.js will patch all possible macroTask and DomEvents
 * user can disable parts of macroTask/DomEvents patch by setting following flags
 */

 // (window as any).__Zone_disable_requestAnimationFrame = true; // disable patch requestAnimationFrame

 // (window as any).__Zone_disable_on_property = true; // disable patch onProperty such as onclick

 // (window as any).__zone_symbol__BLACK_LISTED_EVENTS = ['scroll', 'mousemove']; // disable patch specified eventNames

 /***************************************************************************************************
 * Zone JS is required by default for Angular itself.
 */
import 'zone.js/dist/zone';  // Included with Angular CLI.

/***************************************************************************************************
 * APPLICATION IMPORTS
 */

显然，在使用IE 5的任何情况下，使用Angular 11都不是一个很明智的决定。但是，如果您确实需要支持IE 5，则可以遵循上述步骤进行操作。