Uncaught (in promise) TypeError: Cannot read property 'toLowerCase' of undefined

[malvika1596]

Hi,
I am seeing this error in console of browser-

Uncaught (in promise) TypeError: Cannot read property 'toLowerCase' of undefined
at ReactTags.js:485
at Array.filter ()
at ReactTags.filteredSuggestions (ReactTags.js:484)
at ReactTags.updateSuggestions (ReactTags.js:518)
at ReactTags.componentDidUpdate (ReactTags.js:118)
at commitLifeCycles (react-dom.development.js:20684)
at commitLayoutEffects (react-dom.development.js:23426)
at HTMLUnknownElement.callCallback (react-dom.development.js:3945)
at Object.invokeGuardedCallbackDev (react-dom.development.js:3994)
at invokeGuardedCallback (react-dom.development.js:4056)

The above error occurred in the component:

at ReactTags (http://localhost:8888/ivt-react/dev/app.js:75512:6)
at DndProvider (http://localhost:8888/ivt-react/dev/app.js:68434:24)
at WithContext
at div
at div
at Tags (http://localhost:8888/ivt-react/dev/app.js:76323:6)
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at div
at SearchTags (http://localhost:8888/ivt-react/dev/app.js:88868:6)
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at div
at ConnectedField (http://localhost:8888/ivt-react/dev/app.js:38105:32)
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at Connect(ConnectedField)
at Field (http://localhost:8888/ivt-react/dev/app.js:39975:27)
at Hoc (http://localhost:8888/ivt-react/dev/app.js:39182:32)
at Field
at SearchTagsField (http://localhost:8888/ivt-react/dev/app.js:88959:6)
at SearchTagsValidated
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at div
at GridCell (http://localhost:8888/ivt-react/dev/app.js:63432:6)
at div
at GridRow (http://localhost:8888/ivt-react/dev/app.js:63494:6)
at div
at div
at GridCell (http://localhost:8888/ivt-react/dev/app.js:63432:6)
at div
at GridRow (http://localhost:8888/ivt-react/dev/app.js:63494:6)
at div
at Grid (http://localhost:8888/ivt-react/dev/app.js:63536:6)
at form
at SearchForm (http://localhost:8888/ivt-react/dev/app.js:89822:6)
at Form (http://localhost:8888/ivt-react/dev/app.js:41745:42)
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at Connect(Form(SearchForm))
at ReduxForm (http://localhost:8888/ivt-react/dev/app.js:42484:44)
at Hoc (http://localhost:8888/ivt-react/dev/app.js:39182:32)
at ReduxForm
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at div
at SearchComponent (http://localhost:8888/ivt-react/dev/app.js:90115:6)
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at Route (http://localhost:8888/ivt-react/dev/app.js:78638:30)
at Switch (http://localhost:8888/ivt-react/dev/app.js:78844:30)
at div
at div
at App (http://localhost:8888/ivt-react/dev/app.js:99972:6)
at ConnectFunction (http://localhost:8888/ivt-react/dev/app.js:31886:37)
at C (http://localhost:8888/ivt-react/dev/app.js:78899:38)
at Router (http://localhost:8888/ivt-react/dev/app.js:78297:31)
at BrowserRouter (http://localhost:8888/ivt-react/dev/app.js:78962:36)
at Provider (http://localhost:8888/ivt-react/dev/app.js:31498:21)

I have dependencies installed-

"react": "17.0.2",
"react-dnd": "14.0.2",
"react-dnd-html5-backend": "14.0.0",
"react-dom": "17.0.2",

What is the issue here exactly? Can someone help me please? Kindly tell me if there is more info needed here.

Thanks.

[ad1992]

Hi @malvika1596, when are you getting this error ? do you mind sharing an code sandbox example ?

[malvika1596]

Hi @ad1992, In the legacy app i am working on, while upgrading all the dependencies in the app, I upgraded already present react-tag-input to its latest version from "4.9.1", this error was showing up in console and page didn't load too. For right now, I have restored it back to "4.9.1" and the app is back to running.
It could have been due to the redux-form library present in the parent class or many updates in the component itself. I wasn't able to debug more and due to time constraint, I needed to find the solution. You can close this issue for now.
Thanks, have a good day!

[realPrimoh]

I got this error when there was a null value in the tags array or when an id was undefined within a tag in the tags array.