Tiresome Console Error from Express?

[cliff-bentley]

Any suggestions?

Trying to work through the lessons, but keep getting this console error that wastes 1.5 hours per lesson. Am 99% certain it comes from Express. Don't know what causes the error because it comes and goes inexplicably. Source code doesn't seem to be the problem. The requested page always renders perfectly, the data set logs in terminal, then the verbose terminal error logs. Here are 4 things I've done to "fix" the problem:

1. "Fixed" code that essentially changed nothing (readability, ES6 semantics, etc.). Re-started node and problem disappeared.
2. Removed the code (still) in lesson 17, main.js @line 42. That call, res.render("subscribers", { subscribers: req.data });, seems to be redundant to the same call in getAllSubscribers.
3. Last night, ran rm -rf node_modules then npm i. Problem disappeared, again no code changes.
4. Today the error reappeared. I usually launch directly to http://localhost:3000/subscribers. So I went from there to a couple other routes. Went back to subscribers and the console was clean. Stopped node, re-started node main.js or npm start, it doesn't matter. Went to http://localhost:3000/subscribers - errors re-appear.

Not fun. This is the error copied from my terminal:
`ERROT state: Error: Failed to lookup view "404 | The page does not exist!" in views directory "/home/myHome/develop/recipe_app/views"
at Function.render (/home/myHome/develop/recipe_app/node_modules/express/lib/application.js:580:17)
at ServerResponse.render (/home/myHome/develop/recipe_app/node_modules/express/lib/response.js:1012:7)
at ServerResponse.res.render (/home/myHome/develop/recipe_app/node_modules/express-ejs-layouts/lib/express-layouts.js:77:18)
at exports.respondNoResourceFound (/home/myHome/develop/recipe_app/controllers/errorController.js:19:8)
at Layer.handle [as handle_request] (/home/myHome/develop/recipe_app/node_modules/express/lib/router/layer.js:95:5)
at trim_prefix (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:317:13)
at /home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:335:12)
at next (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:275:10)
at Layer.handle [as handle_request] (/home/myHome/develop/recipe_app/node_modules/express/lib/router/layer.js:91:12)
at trim_prefix (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:317:13)
at /home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:335:12)
at next (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:275:10)
at jsonParser (/home/myHome/develop/recipe_app/node_modules/body-parser/lib/types/json.js:110:7)
at Layer.handle [as handle_request] (/home/myHome/develop/recipe_app/node_modules/express/lib/router/layer.js:95:5)

TypeError [ERR_INVALID_ARG_VALUE]: The argument 'id' must be a non-empty string. Received ''
at Module.require (internal/modules/cjs/loader.js:1037:11)
at require (internal/modules/cjs/helpers.js:77:18)
at new View (/home/myHome/develop/recipe_app/node_modules/express/lib/view.js:81:14)
at Function.render (/home/myHome/develop/recipe_app/node_modules/express/lib/application.js:570:12)
at ServerResponse.render (/home/myHome/develop/recipe_app/node_modules/express/lib/response.js:1012:7)
at ServerResponse.res.render (/home/myHome/develop/recipe_app/node_modules/express-ejs-layouts/lib/express-layouts.js:77:18)
at exports.respondInternalError (/home/myHome/develop/recipe_app/controllers/errorController.js:29:8)
at Layer.handle_error (/home/myHome/develop/recipe_app/node_modules/express/lib/router/layer.js:71:5)
at trim_prefix (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:315:13)
at /home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:284:7
at Function.process_params (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:335:12)
at next (/home/myHome/develop/recipe_app/node_modules/express/lib/router/index.js:275:10)
at /home/myHome/develop/recipe_app/node_modules/express-ejs-layouts/lib/express-layouts.js:80:40
at Function.render (/home/myHome/develop/recipe_app/node_modules/express/lib/application.js:582:14)
at ServerResponse.render (/home/myHome/develop/recipe_app/node_modules/express/lib/response.js:1012:7)
at ServerResponse.res.render (/home/myHome/develop/recipe_app/node_modules/express-ejs-layouts/lib/express-layouts.js:77:18)
`