Uncaught TypeError: Cannot read property 'isHiddenDay' of undefined

[YogliB]

I've created a Svelte implementation of FullCalendar and I have issues upgrading to v5.

I use rollup as my builder and a postcss plugin for the styles, and tried to follow this guide.

I try to initialize the calendar with these options:

let options = {
	initialView: 'dayGridMonth',
	plugins: [dayGridPlugin],
};

This is what I get in the browser's console:

main.js:8102 Uncaught TypeError: Cannot read property 'isHiddenDay' of undefined
    at new DaySeriesModel (main.js:8102)
    at DayTableView.buildDayTableModel (main.js:1080)
    at DayTableView.buildDayTableModel (main.js:983)
    at DayTableView.render (main.js:1069)
    at T (preact.module.js:1)
    at g (preact.module.js:1)
    at j (preact.module.js:1)
    at T (preact.module.js:1)
    at g (preact.module.js:1)
    at T (preact.module.js:1)

• This is the component implementation.
• I can't actually upload a live demo since I need a postcss plugin to handle the css-in-js.

[lukasz-malicki-wrx]

duplicated issue?
fullcalendar/fullcalendar-react#78

[acerix]

It sounds like there may be a bug here seeing how others reported the same in the other issue. But I don't get any error using the example project, so you can try that to find what is causing the error and make a stripped-down demo.

https://github.com/fullcalendar/fullcalendar-example-projects/tree/master/webpack

There's also a demo with rollup:

https://github.com/fullcalendar/fullcalendar-example-projects/tree/master/rollup

[janswist]

I have the same issue:

From what I understand it begins here

fullcalendar/packages/common/src/common/DaySeriesModel.ts

Line 26 in d3a2b13

if (dateProfileGenerator.isHiddenDay(date)) {

This is really frustrating because it started when I tried to add custom button. When unsuccessful I went back to "working" code, but error still shows up. Tried to reproduce it, but no luck. Maybe it's deeper, beyond calendar (webpack?).

What helped me with error was removing all fullcalendar dependencies from package.json, npm i, then add them back and again npm i, but nevertheless that should be inspected.

[irfanonk]

I have got exact the same issue,(Cannot read property 'isHiddenDay' of undefined)
so i searched and ended up here. then I realized that there wasn't any "@fullcalendar/timegrid": "^5.1.0", in my package.json even I installed with npm install @fullcalendar/timegrid.
so then I installed with npm install --save @fullcalendar/timegrid (with --save) and made sure that it's in package.json dependencies, that eventually solved problem.

[janswist]

I have got exact the same issue,(Cannot read property 'isHiddenDay' of undefined)
so i searched and ended up here. then I realized that there wasn't any "@fullcalendar/timegrid": "^5.1.0", in my package.json even I installed with npm install @fullcalendar/timegrid.
so then I installed with npm install --save @fullcalendar/timegrid (with --save) and made sure that it's in package.json dependencies, that eventually solved problem.

How come --save made it work? 🤔

[lulu-dirou]

I have got exact the same issue,(Cannot read property 'isHiddenDay' of undefined)

[arshaw]

I see a lot of people complaining about this bug, but nobody posting any reduced test cases, so sadly we won't be able to fix

[janswist]

I see a lot of people complaining about this bug, but nobody posting any reduced test cases, so sadly we won't be able to fix

Because it's hard to reproduce it. I tried myself once, but error didn't appear then so I gave up.

[dev-assassin]

I have got exact the same issue,(Cannot read property 'isHiddenDay' of undefined)
so i searched and ended up here. then I realized that there wasn't any "@fullcalendar/timegrid": "^5.1.0", in my package.json even I installed with npm install @fullcalendar/timegrid.
so then I installed with npm install --save @fullcalendar/timegrid (with --save) and made sure that it's in package.json dependencies, that eventually solved problem.

@irfanonk
yes, it works for me.
thanks.
it saves my times and money ;)

[YogliB]

@arshaw

This is the leanest repro I could have come up with, hope this helps.

[jsaarest]

Got this problem after updating to fullcalendar 5.3.0, ran npm install --save @fullcalendar/react and it started running again :)

[eli-xciv]

I've ran into this problem as well last week. I've tried @irfanonk 's suggestion but that did not work for me. And the packages are listed in package.json.