Please help clueless professor with Typescript node modules in PHPStorm

Hello.

First, allow me to apologize. I am not a professional programmer and my understanding is often rudimentary.  I am a technology teacher at a university, and there is much I do not know.  Please treat me like a newbie despite my 30 years of technology experience ;→)

I have been using PHPStorm for several years (Version 2020.2.1, Build #PS-202.6948.87).  For the first time, however, I'd like to edit some typescript code.  When I try to open up a typescript file, I get the following error:

Error:Initialization error (typescript). Cannot set property parseJsonConfigFileContent of #<Object> which has only a getter
TypeError: Cannot set property parseJsonConfigFileContent of #<Object> which has only a getter
   at overrideParseJsonConfigFileContent (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\session\old\ts-project-service-21.js:37:40)
   at Object.extendProjectService21 (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\session\old\ts-project-service-21.js:6:5)
   at Object.createSessionLatestClass (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\ts-session-latest.js:21:29)
   at Object.createSessionClass (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\ts-session-provider.js:29:36)
   at TypeScriptLanguagePlugin.createSessionClass (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\ts-plugin.js:116:38)
   at TypeScriptLanguagePlugin.getSession (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\ts-plugin.js:109:33)
   at new TypeScriptLanguagePlugin (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\ts-plugin.js:20:30)
   at TypeScriptLanguagePluginFactory.create (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\typescript\ts-plugin.js:128:40)
   at Interface.<anonymous> (C:\Program Files\JetBrains\PhpStorm 2020.2.1\plugins\JavaScriptLanguage\jsLanguageServicesImpl\js-language-service.js:82:52)
   at Interface.emit (node:events:514:28)

I have reviewed many of the posts that seem to relate to this issue, but I'm afraid the solutions are over my head (and I'm never even sure if the problem is the same). 

It seems to me that either I'm missing some kind of plugin that I should have, or the plugin I have is old and obsolete and doesn't work.  Or perhaps PHPStorm doesn't support Typescript anymore.  Or maybe I'm simply missing an option in the preferences.  The bottom line is that I'm at a loss and can't figure out what to do next.  Can anyone help me?  And please be specific.  

Thank you in advance for your help.  Much appreciated.

CJ