IllegalArgumentException when creating new Group in 'phone storage'

[I-Dont-Remember]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

1.4.0

Affected Android/Custom ROM version

Android 16

Affected device model

Pixel 6a

How did you install the app?

Google Play Store

Steps to reproduce the bug

This bug was appearing originally when trying to add new contacts or edit old ones, but it can also be easily triggered with groups:

1. Go to Groups
2. Create a new group with name Test
3. In the popup for "Create group under account" , choose Phone storage rather than Phone storage (not visible by other apps).

Can also do minimal contact:

1. Create new contact
2. fill in just the first name

Expected behavior

A. group is created, OR
B. contact with a single field is created

Actual behavior

💥 A Toast fires with the cut off message: Error: java.lang.illegalArgumentException: Cannot add contacts...

Screenshots/Screen recordings

I'd add one, but it just shows the toast and nothing else useful. Happy to add if you really want it as assurance.

Additional information

I've only had the app since Feb/March 2025, and in the early months I had no trouble loading contacts into phone storage or editing them (all of my contacts in the phone storage location, rather than not visible - so it must have been working at one point). I only noticed this error start occurring within the last 3 weeks - but it could have started before then, I don't think I've added many contacts in last ~4 months.

If there is an easy way to get a more useful stack trace, I'm happy to try and dig in to make things easier to trace down.