diff --git a/Lite.Tests/AgedDatabaseMigrationTests.cs b/Lite.Tests/AgedDatabaseMigrationTests.cs
new file mode 100644
index 000000000..c106aaf82
--- /dev/null
+++ b/Lite.Tests/AgedDatabaseMigrationTests.cs
@@ -0,0 +1,134 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using DuckDB.NET.Data;
+using PerformanceMonitorLite.Database;
+using Xunit;
+
+namespace PerformanceMonitorLite.Tests;
+
+/// <summary>
+/// #2748: a real user's database, aged past v47, failed both the v48 and v53 migrations on upgrade
+/// to v3.6.0.0. Both errors were logged as "non-fatal" and the migration chain nominally completed to
+/// v56, but the app then failed to start — the two swallowed failures left the database missing
+/// state later code assumes is there. These tests seed the exact aged-database preconditions that
+/// triggered each failure and assert the upgrade both succeeds AND leaves the database actually
+/// correct, not just quietly incomplete.
+/// </summary>
+public class AgedDatabaseMigrationTests : IDisposable
+{
+    private readonly string _tempDir;
+    private readonly string _dbPath;
+
+    public AgedDatabaseMigrationTests()
+    {
+        _tempDir = Path.Combine(Path.GetTempPath(), "LiteTests_" + Guid.NewGuid().ToString("N")[..8]);
+        Directory.CreateDirectory(_tempDir);
+        _dbPath = Path.Combine(_tempDir, "test.duckdb");
+    }
+
+    public void Dispose()
+    {
+        try
+        {
+            if (Directory.Exists(_tempDir))
+                Directory.Delete(_tempDir, recursive: true);
+        }
+        catch
+        {
+            /* Best-effort cleanup */
+        }
+    }
+
+    /// <summary>
+    /// v48 drops NOT NULL from three server_properties columns. On any database that has completed a
+    /// prior startup, Schema.GetAllIndexStatements() already created idx_server_properties_time — a
+    /// real, persisted index on (server_id, collection_time) — and DuckDB's ALTER COLUMN dependency
+    /// check refuses to touch a table with ANY index on it, even one naming none of the altered columns
+    /// (confirmed empirically: a plain SELECT * archive view does NOT trigger this, only the index
+    /// does). Seeds that exact precondition and asserts the upgrade both completes AND the column is
+    /// actually nullable afterward, not merely that it didn't throw.
+    /// </summary>
+    [Fact]
+    public async Task UpgradeFromV47_DropsServerPropertiesNotNull_EvenWithAPreExistingIndex()
+    {
+        using (var seed = new DuckDBConnection($"Data Source={_dbPath}"))
+        {
+            await seed.OpenAsync();
+            await ExecAsync(seed, "CREATE TABLE schema_version (version INTEGER NOT NULL)");
+            await ExecAsync(seed, "INSERT INTO schema_version VALUES (47)");
+            await ExecAsync(seed, @"CREATE TABLE server_properties (
+                server_id INTEGER NOT NULL,
+                collection_time TIMESTAMP NOT NULL,
+                cpu_count INTEGER NOT NULL,
+                hyperthread_ratio INTEGER NOT NULL,
+                physical_memory_mb BIGINT NOT NULL
+            )");
+            await ExecAsync(seed, "INSERT INTO server_properties VALUES (1, current_timestamp, 4, 1, 16384)");
+            /* The real dependent object: DuckDbSchemaGenerator.CreateIndex's default case for any
+               collector table, including server_properties, is exactly this index/column shape. */
+            await ExecAsync(seed, "CREATE INDEX idx_server_properties_time ON server_properties(server_id, collection_time)");
+        }
+
+        var initializer = new DuckDbInitializer(_dbPath);
+        await initializer.InitializeAsync();
+
+        using var verify = new DuckDBConnection($"Data Source={_dbPath}");
+        await verify.OpenAsync();
+
+        /* The real assertion: a permission-free collector row (NULL hardware columns) must actually be
+           insertable now. Before the fix, the dependency error silently left the NOT NULL constraint in
+           place, so this insert would throw — the exact failure mode #2748's v48 fix exists to prevent. */
+        await ExecAsync(verify, "INSERT INTO server_properties VALUES (2, current_timestamp, NULL, NULL, NULL)");
+
+        using var countCmd = verify.CreateCommand();
+        countCmd.CommandText = "SELECT COUNT(*) FROM server_properties WHERE server_id = 2 AND cpu_count IS NULL";
+        Assert.Equal(1L, Convert.ToInt64(await countCmd.ExecuteScalarAsync()));
+    }
+
+    /// <summary>
+    /// v53 adds two columns to config_database_state_expected via ALTER TABLE. That table was never
+    /// given its own numbered migration — it only exists because Schema.GetAllTableStatements()
+    /// unconditionally creates it, which does not run until AFTER migrations. A database old enough to
+    /// predate the table (introduced by #2166/#2203, well after v47) hits the ALTER before the table
+    /// exists at all. Seeds a v47 database with NO config_database_state_expected table, and asserts
+    /// the upgrade both completes AND the table exists afterward with both new columns present and
+    /// actually writable.
+    /// </summary>
+    [Fact]
+    public async Task UpgradeFromV47_CreatesConfigDatabaseStateExpected_WhenItPredatesTheTable()
+    {
+        using (var seed = new DuckDBConnection($"Data Source={_dbPath}"))
+        {
+            await seed.OpenAsync();
+            await ExecAsync(seed, "CREATE TABLE schema_version (version INTEGER NOT NULL)");
+            await ExecAsync(seed, "INSERT INTO schema_version VALUES (47)");
+            /* Deliberately absent: config_database_state_expected. #2748's real-world database was old
+               enough that this table had never been created — that is the entire bug. */
+        }
+
+        var initializer = new DuckDbInitializer(_dbPath);
+        await initializer.InitializeAsync();
+
+        using var verify = new DuckDBConnection($"Data Source={_dbPath}");
+        await verify.OpenAsync();
+
+        /* The real assertion: the columns v53 exists to add must actually be writable afterward — this
+           is what DuckDbAlertHistoryStore's UPDATE (the database-state alert's edge-trigger memory)
+           depends on, and what #2748's user's app crashed trying to do. */
+        await ExecAsync(verify,
+            "INSERT INTO config_database_state_expected (server_id, database_name, expected_state, last_alerted_state, last_alerted_at) " +
+            "VALUES (1, 'TestDb', 'ONLINE', 'ONLINE', current_timestamp)");
+
+        using var countCmd = verify.CreateCommand();
+        countCmd.CommandText = "SELECT COUNT(*) FROM config_database_state_expected WHERE server_id = 1 AND database_name = 'TestDb'";
+        Assert.Equal(1L, Convert.ToInt64(await countCmd.ExecuteScalarAsync()));
+    }
+
+    private static async Task ExecAsync(DuckDBConnection connection, string sql)
+    {
+        using var cmd = connection.CreateCommand();
+        cmd.CommandText = sql;
+        await cmd.ExecuteNonQueryAsync();
+    }
+}
diff --git a/Lite/Database/DuckDbInitializer.cs b/Lite/Database/DuckDbInitializer.cs
index 304854329..999d1c02d 100644
--- a/Lite/Database/DuckDbInitializer.cs
+++ b/Lite/Database/DuckDbInitializer.cs
@@ -1289,6 +1289,25 @@ database has to have the constraint dropped. New databases get it from the
                     generator. Column types and ordinals are unchanged, so the positional appender
                     and old parquet are unaffected. */
             _logger?.LogInformation("Running migration to v48: server_properties hardware columns become nullable");
+
+            /* #2748: on any database that has ever completed a prior startup, DuckDbSchemaGenerator.CreateIndex's
+               default case already created idx_server_properties_time ON server_properties(server_id,
+               collection_time) — a real catalog object persisted in the .duckdb file, surviving a restart.
+               DuckDB's ALTER COLUMN dependency check refuses to touch a table with ANY index on it, even one
+               that names none of the altered columns — confirmed empirically, not merely by reading the error
+               text: "Dependency Error: Cannot alter entry ... because there are entries that depend on it."
+               (An archive view on the table does NOT trigger this — only the index does.) Drop the index
+               first; Schema.GetAllIndexStatements()'s loop (called unconditionally right after migrations,
+               inside this same InitializeAsync) recreates it, so nothing is left dangling. */
+            try
+            {
+                await ExecuteNonQueryAsync(connection, "DROP INDEX IF EXISTS idx_server_properties_time");
+            }
+            catch (Exception ex)
+            {
+                _logger?.LogWarning("Migration to v48 could not drop idx_server_properties_time ahead of the ALTERs (non-fatal, the ALTERs below may still fail): {Error}", ex.Message);
+            }
+
             foreach (var column in new[] { "cpu_count", "hyperthread_ratio", "physical_memory_mb" })
             {
                 try
@@ -1384,12 +1403,24 @@ CreateArchiveViewsAsync via ArchivableTables. */
             _logger?.LogInformation("Running migration to v53: adding the alerted-state memory to config_database_state_expected");
             try
             {
+                /* #2748: config_database_state_expected itself was never given its own numbered migration —
+                   it only exists because Schema.GetAllTableStatements() unconditionally CREATE TABLE IF NOT
+                   EXISTS-es it, which does not run until AFTER RunMigrationsAsync returns. A database old
+                   enough to predate the table (upgrading through v53 for the first time) hits this ALTER
+                   before that later step ever creates it. CreateDatabaseStateExpectedTable is itself
+                   idempotent, so calling it here is a no-op for anyone who already has the table (from a
+                   prior run) and a correct fresh create — new columns included — for anyone who does not. */
+                await ExecuteNonQueryAsync(connection, Schema.CreateDatabaseStateExpectedTable);
                 await ExecuteNonQueryAsync(connection, "ALTER TABLE config_database_state_expected ADD COLUMN IF NOT EXISTS last_alerted_state VARCHAR");
                 await ExecuteNonQueryAsync(connection, "ALTER TABLE config_database_state_expected ADD COLUMN IF NOT EXISTS last_alerted_at TIMESTAMP");
             }
-            catch
+            catch (Exception ex)
             {
-                /* Table doesn't exist yet — will be created with the full schema below */
+                /* The CREATE above means "table doesn't exist yet" can no longer be the cause — a catch here
+                   now means something else went wrong. Log it rather than swallow it silently, matching every
+                   sibling migration block; this whole PR exists because a silently-swallowed failure here is
+                   exactly what left #2748's database unfixed for two releases. */
+                _logger?.LogWarning("Migration to v53 encountered an error (non-fatal): {Error}", ex.Message);
             }
         }