要約

You are trying to add or use a custom field on any screen, and see the error message: 

"Description can't exceed 255 characters"

Edit field description to fewer than 255 characters

Jira has a hard character limit for custom field descriptions. This limit cannot be adjusted in Jira Cloud.

If you're seeing this error, you will need to edit the field's description to a value smaller than 255 characters.

1. Navigate to Settings > Issues > Custom fields
   1. Or, visit the link https://<your_instance_here>.atlassian.net/secure/admin/ViewCustomFields.jspa
2. Search for the custom field by name
3. Select ... (more options) > Edit details
4. Adjust the field's description
5. 変更を保存

Alternative: Use a different field type

If necessary, you can use a multi-line Text field, which supports ~32000 characters.