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"No available users" message despite slot available

Open monty241 opened this issue 9 months ago • 19 comments

Issue Summary

An error "No available users" occurs despite the slot being available and already selected.

English text:

Could not book the meeting. No available users found. Could you try another time slot?

Steps to Reproduce

  1. Find a free slot in the calendar (red arrow).
  2. Check that the time is a free slot (red arrow).
  3. Fill out.
  4. Error (see picture).

Error does not occur always, maybe 50% of conversions fails.

Agenda linked through ICS with Proton Calendar.

Expectation: meeting can be confirmed.

Technical details

  • Google Chrome, last production version.
  • Cal.com Teams Plan

Image

See also

This does not concern a recurring event, just a one off, so https://github.com/calcom/cal.com/issues/18072 might not apply.

monty241 avatar Mar 27 '25 15:03 monty241

Issue has already been reported through chat some time ago. Allegedly work is in progress for this.

monty241 avatar Mar 27 '25 15:03 monty241

Do you have a link to follow on that work in progress? I have the exact same use case and issue.

ldealmei avatar Mar 28 '25 13:03 ldealmei

No, there is no link. All communication took place through chat. This ticket was created to ease tracking.

monty241 avatar Mar 30 '25 10:03 monty241

Thanks for reporting this, I tried reproducing the issue multiple times but couldn't replicate it. Since it happens intermittently, could you share more details? For example, does it occur with specific time slots or users? Let me know, and I’d be happy to dig deeper

soham901 avatar Apr 02 '25 15:04 soham901

It can be reproduced as follows:

  • go to https://go.invantive.com/book/introduction
  • currently there is a slot free on April 21 14:00
  • choose that one
  • enter some test data
  • book
  • "Could not book the meeting"

See picture.

Image

The proton calendar displays (GMT+2):

Image

The ICS source (credentials removed):

https://calendar.proton.me/api/calendar/v1/url/...==/calendar.ics?CacheKey=...%3D%3D

The ICS contains for the meeting of 12:00-14:00:


BEGIN:VEVENT
UID:[email protected]
DTSTAMP:20250401T152555Z
DTSTART;TZID=Europe/Amsterdam:20250314T120000
DTEND;TZID=Europe/Amsterdam:20250314T140000
RRULE:FREQ=DAILY
EXDATE;TZID=Europe/Amsterdam:20250414T120000
EXDATE;TZID=Europe/Amsterdam:20250424T120000
EXDATE;TZID=Europe/Amsterdam:20250425T120000
EXDATE;TZID=Europe/Amsterdam:20250428T120000
SEQUENCE:1
SUMMARY:Busy
EXDATE;TZID=Europe/Amsterdam:20250414T120000
EXDATE;TZID=Europe/Amsterdam:20250424T120000
EXDATE;TZID=Europe/Amsterdam:20250425T120000
EXDATE;TZID=Europe/Amsterdam:20250428T120000
STATUS:CONFIRMED
END:VEVENT

When there is some debugging feature to be activated: will be happy to do so.

monty241 avatar Apr 02 '25 16:04 monty241

@monty241 Thanks for the detailed steps, I visited the page you linked and tried booking the slot, and as expected, it throws the error. However, when testing locally with 22+ manual tests across different scenarios, I couldn't reproduce the issue. Based on the current code, it seems like this issue might have already been fixed. If you still experience this in the next release, feel free to update this thread, and we’ll look into it again

soham901 avatar Apr 02 '25 19:04 soham901

Great! I will retest.

From the bottom of left menu I see current version is v.5.1.14-h-ea7313d with a link to https://github.com/calcom/cal.com/commit/ea7313d7c5109c129adf105c688298c4f13ec744.

What release label should it be in and what is approximate release frequency when everything goes smoothly?

monty241 avatar Apr 02 '25 19:04 monty241

Release Label: Version v.5.1.14-h indicates a minor update or hotfix.

Release Frequency: Minor updates ( v.5.1.x ) are typically released every few weeks, or approximately once a month, when development proceeds smoothly.

soham901 avatar Apr 03 '25 01:04 soham901

I have the exact same issue, and I still have the issue with the version v5.1.15-h-3b954ba. What's the version you successfully tested locally?

ldealmei avatar Apr 04 '25 10:04 ldealmei

@ldealmei i was using this: https://github.com/calcom/cal.com/commit/93621baea54f0801fd452c942131a99a1a054690

soham901 avatar Apr 05 '25 07:04 soham901

Then the issue is not fixed because that commit has been deployed in v5.1.12 and we are currently at v5.1.17 and I still get the error. What can we do to help in reproducing the issue?

ldealmei avatar Apr 08 '25 12:04 ldealmei

Retested on v.5.2.7-h-c06cd42. Issue still occurs (user reported it, was able to reproduce).

monty241 avatar Apr 28 '25 08:04 monty241

I'm also seeing this issue. version is v.5.3.4-h-53a0679, on the free plan, using firefox on NixOS. This is the response header:

HTTP/2 409 date: Sat, 24 May 2025 18:54:51 GMT content-type: application/json; charset=utf-8 content-length: 44 cf-ray: 944f00fbc812dd19-ATL cf-cache-status: DYNAMIC cache-control: public, max-age=0, must-revalidate etag: "1ajn3qlfsb18" strict-transport-security: max-age=63072000 vary: Accept-Encoding referrer-policy: no-referrer-when-downgrade x-content-type-options: nosniff x-matched-path: /api/book/event x-vercel-cache: MISS x-vercel-id: iad1:iad1:iad1::cle1::nncsd-1748112890482-88e67730897e server: cloudflare X-Firefox-Spdy: h2

I had multiple proton calendars linked through ICS and booking worked when I removed them.

apalermo01 avatar May 24 '25 19:05 apalermo01

Hey, I still have this issue, when I "Toggle the calendars you want to check for conflicts to prevent double bookings.", it works, the public link to book an appointment "check for conflicts". BUT

Image

But, it doesn't work, it doesn't book, there is still : "Could not book the meeting. No available users found. Could you try another time slot?"

Image

And then if I disable the "checking for conflicts", it works. But without my personal calendar.

Just to say, if someone take an appointment, it won't be available anymore by the public link to book an appointment. That's a good think.

botlane-feeder avatar Sep 05 '25 08:09 botlane-feeder

Check this comment for a workaround until this issue is fixed: https://github.com/calcom/cal.com/issues/23391#issuecomment-3344101044

ldealmei avatar Sep 28 '25 18:09 ldealmei

It seems that it works again. On the online version 5.7.11

I just tried to connect my proton calendar. On the public meeting link, my proton appointment is "checked for conflicts". And when I try to schedule an appointment by the public meeting link, it works :

  • It doesn't print "Could not book the meeting. No available users found. Could you try another time slot?"
  • And invitations are sent.

botlane-feeder avatar Oct 13 '25 07:10 botlane-feeder

Not working for me. Tried just now on v.5.7.11-h-eae2711 (Dutch, but same text):

Image

monty241 avatar Oct 13 '25 08:10 monty241

I added a repo case with a live event here: https://github.com/calcom/cal.com/issues/23391#issuecomment-3636439494

nb. This bug is not just a huge inconvenience, it is causing me reputation damage.

Not a good look at all when a busy client and/or their exec. assistants keep getting "no available users" when the promised time band is clearly open on my cal.com

adityaathalye avatar Dec 10 '25 10:12 adityaathalye

Dito, we have to call customers churning else. Due to efforts to disentangle with US tech we prefer cal.com as less US tech, but it is costly and makes our customers associate our company with lack of quality / poor decisions. Bug is open for 8+ months.

monty241 avatar Dec 10 '25 12:12 monty241