diff --git a/src/Common/src/CoreLib/System/Globalization/CalendarData.Unix.cs b/src/Common/src/CoreLib/System/Globalization/CalendarData.Unix.cs
index 80e385376d05..a8c69f86e644 100644
--- a/src/Common/src/CoreLib/System/Globalization/CalendarData.Unix.cs
+++ b/src/Common/src/CoreLib/System/Globalization/CalendarData.Unix.cs
@@ -39,7 +39,11 @@ private bool LoadCalendarDataFromSystem(string localeName, CalendarId calendarId
             // TODO-NULLABLE: these can return null but are later replaced with String.Empty or other non-nullable value
             result &= GetCalendarInfo(localeName, calendarId, CalendarDataType.NativeName, out this.sNativeName!);
             result &= GetCalendarInfo(localeName, calendarId, CalendarDataType.MonthDay, out this.sMonthDay!);
-            this.sMonthDay = NormalizeDatePattern(this.sMonthDay);
+
+            if (this.sMonthDay != null)
+            {
+                this.sMonthDay = NormalizeDatePattern(this.sMonthDay);
+            }
 
             result &= EnumDatePatterns(localeName, calendarId, CalendarDataType.ShortDates, out this.saShortDates!);
             result &= EnumDatePatterns(localeName, calendarId, CalendarDataType.LongDates, out this.saLongDates!);
diff --git a/src/Common/src/CoreLib/System/Globalization/CalendarData.cs b/src/Common/src/CoreLib/System/Globalization/CalendarData.cs
index 131dd6b31550..93ec643b6725 100644
--- a/src/Common/src/CoreLib/System/Globalization/CalendarData.cs
+++ b/src/Common/src/CoreLib/System/Globalization/CalendarData.cs
@@ -112,7 +112,8 @@ internal CalendarData(string localeName, CalendarId calendarId, bool bUseUserOve
 
             if (!LoadCalendarDataFromSystem(localeName, calendarId))
             {
-                Debug.Fail("[CalendarData] LoadCalendarDataFromSystem call isn't expected to fail for calendar " + calendarId + " locale " + localeName);
+                // LoadCalendarDataFromSystem sometimes can fail on Linux if the installed ICU package is missing some resources.
+                // The ICU package can miss some resources in some cases like if someone compile and build the ICU package manually or ICU has a regression.
 
                 // Something failed, try invariant for missing parts
                 // This is really not good, but we don't want the callers to crash.