Fatal TypeError if the config entity does not exist

@jwilson3, is this happening following a new install of 2.0.0, or an upgrade from 8.x-1.x?

There are some notes in the other issue.

Dear colleagues,

We had same issue but we always had version 2.0.0. We discovered because no daterange compact entity was created.

When no compact data is defined here: /admin/config/regional/daterange-compact-format

Then a message appears:
TypeError: Drupal\daterange_compact\DateRangeCompactFormatter::derivePatterns(): Argument #1 ($format) must be of type Drupal\daterange_compact\Entity\DateRangeCompactFormatInterface, null given, called in /home/abel-santos-corral/openeuropa/era-era-dev/web/modules/contrib/daterange_compact/src/DateRangeCompactFormatter.php on line 63 in Drupal\daterange_compact\DateRangeCompactFormatter->derivePatterns() (line 96 of modules/contrib/daterange_compact/src/DateRangeCompactFormatter.php).

The error can be reproduced eliminating all the configurations there.

So maybe at this point:
$patterns = $this->derivePatterns($format, $start_timestamp, $end_timestamp, $timezone);

Of function formatTimestampRange there must be any check to avoid that fatal error to happen and be more robust.

Please reproduce and check if the fatal error can be avoided so the site gets not broken in this case. Even though there's configuration provided by the module, a user can delete the configurations so the problem could appear from time to time. So better to have that controlled somehow.

Thanks in advance.

Is there a solution for this issue, yet? I seem to have run into it myself with Drupal 9.5.11 and daterange_compact 2.0.1.

Never mind - I've learned that the compact date formats I had set up must not have transferred when upgrading Drupal from 8 to 9, or perhaps when upgrading this module. After re-creating my default compact format, everything worked again.

This error happens when the formatter is passed a non-existent config entity ID, as described in #8.

I looked at how the core date formatter handles this situation. If the format doesn't exist or is invalid, a fallback date format is used. This `fallback` format is included as part of the module's default configuration and locked.

So it would make sense for this module to behave the same way. Added to 2.1.0.