diff --git a/src/BUTR.CrashReport.Server.v13/HtmlHandlerV13.cs b/src/BUTR.CrashReport.Server.v13/HtmlHandlerV13.cs
index c722d86..806516c 100644
--- a/src/BUTR.CrashReport.Server.v13/HtmlHandlerV13.cs
+++ b/src/BUTR.CrashReport.Server.v13/HtmlHandlerV13.cs
@@ -65,7 +65,10 @@ public async Task<IActionResult> UploadHtmlAsync(ControllerBase controller, Canc
         var html = await streamReader.ReadToEndAsync(ct);
         var (valid, version, crashReportModel) = ParseHtml(html);
         if (!valid)
+        {
+            _logger.LogWarning("Invalid HTML");
             return controller.StatusCode(StatusCodes.Status500InternalServerError);
+        }
 
         if (await _dbContext.IdEntities.FirstOrDefaultAsync(x => x.CrashReportId == crashReportModel!.Id, ct) is { } idEntity)
             return controller.Ok($"{_options.BaseUri}/{idEntity.FileId}");
diff --git a/src/BUTR.CrashReport.Server.v13/JsonHandlerV13.cs b/src/BUTR.CrashReport.Server.v13/JsonHandlerV13.cs
index 97182e7..036ee21 100644
--- a/src/BUTR.CrashReport.Server.v13/JsonHandlerV13.cs
+++ b/src/BUTR.CrashReport.Server.v13/JsonHandlerV13.cs
@@ -67,7 +67,10 @@ public async Task<IActionResult> UploadJsonAsync(ControllerBase controller, Canc
             controller.Request.Body = await _gZipCompressor.DecompressAsync(controller.Request.Body, ct);
 
         if (await controller.HttpContext.Request.ReadFromJsonAsync<CrashReportUploadBodyV13>(_jsonSerializerOptions, ct) is not { CrashReport: { } crashReport, LogSources: { } logSources })
+        {
+            _logger.LogWarning("Failed to read JSON body");
             return controller.StatusCode(StatusCodes.Status500InternalServerError);
+        }
 
         if (await _dbContext.IdEntities.FirstOrDefaultAsync(x => x.CrashReportId == crashReport.Id, ct) is { } idEntity)
             return controller.Ok($"{_options.BaseUri}/{idEntity.FileId}");
diff --git a/src/BUTR.CrashReport.Server.v14/HtmlHandlerV14.cs b/src/BUTR.CrashReport.Server.v14/HtmlHandlerV14.cs
index acc9678..5c34d92 100644
--- a/src/BUTR.CrashReport.Server.v14/HtmlHandlerV14.cs
+++ b/src/BUTR.CrashReport.Server.v14/HtmlHandlerV14.cs
@@ -65,7 +65,10 @@ public async Task<IActionResult> UploadHtmlAsync(ControllerBase controller, Canc
         var html = await streamReader.ReadToEndAsync(ct);
         var (valid, version, crashReportModel) = ParseHtml(html);
         if (!valid)
+        {
+            _logger.LogWarning("Invalid HTML");
             return controller.StatusCode(StatusCodes.Status500InternalServerError);
+        }
 
         if (await _dbContext.IdEntities.FirstOrDefaultAsync(x => x.CrashReportId == crashReportModel!.Id, ct) is { } idEntity)
             return controller.Ok($"{_options.BaseUri}/{idEntity.FileId}");
diff --git a/src/BUTR.CrashReport.Server.v14/JsonHandlerV14.cs b/src/BUTR.CrashReport.Server.v14/JsonHandlerV14.cs
index a9b06d2..4e5be06 100644
--- a/src/BUTR.CrashReport.Server.v14/JsonHandlerV14.cs
+++ b/src/BUTR.CrashReport.Server.v14/JsonHandlerV14.cs
@@ -67,7 +67,10 @@ public async Task<IActionResult> UploadJsonAsync(ControllerBase controller, Canc
             controller.Request.Body = await _gZipCompressor.DecompressAsync(controller.Request.Body, ct);
 
         if (await controller.HttpContext.Request.ReadFromJsonAsync<CrashReportUploadBodyV14>(_jsonSerializerOptions, ct) is not { CrashReport: { } crashReport, LogSources: { } logSources })
+        {
+            _logger.LogWarning("Failed to read JSON body");
             return controller.StatusCode(StatusCodes.Status500InternalServerError);
+        }
 
         if (await _dbContext.IdEntities.FirstOrDefaultAsync(x => x.CrashReportId == crashReport.Id, ct) is { } idEntity)
             return controller.Ok($"{_options.BaseUri}/{idEntity.FileId}");
diff --git a/src/BUTR.CrashReport.Server/Controllers/CrashUploadController.cs b/src/BUTR.CrashReport.Server/Controllers/CrashUploadController.cs
index 6344361..74f8042 100644
--- a/src/BUTR.CrashReport.Server/Controllers/CrashUploadController.cs
+++ b/src/BUTR.CrashReport.Server/Controllers/CrashUploadController.cs
@@ -53,7 +53,10 @@ public CrashUploadController(
     public Task<IActionResult> CrashUploadAsync(CancellationToken ct)
     {
         if (Request.ContentLength is not { } contentLength || contentLength < _options.MinContentLength || contentLength > _options.MaxContentLength)
+        {
+            _logger.LogWarning("Content length is invalid: {ContentLength}", Request.ContentLength);
             return Task.FromResult<IActionResult>(StatusCode(StatusCodes.Status500InternalServerError));
+        }
 
         switch (Request.ContentType)
         {
@@ -67,14 +70,18 @@ public Task<IActionResult> CrashUploadAsync(CancellationToken ct)
 
     private async Task<IActionResult> UploadJsonAsync(CancellationToken ct)
     {
-        switch (Request.Headers["CrashReportVersion"])
+        var version = Request.Headers["CrashReportVersion"].ToString();
+        switch (version)
         {
             case "13":
                 return await _jsonHandlerV13.UploadJsonAsync(this, ct);
             case "14":
                 return await _jsonHandlerV14.UploadJsonAsync(this, ct);
             default:
+            {
+                _logger.LogWarning("Crash report version is invalid: {CrashReportVersion}", version);
                 return StatusCode(StatusCodes.Status500InternalServerError);
+            }
         }
     }
 
@@ -109,13 +116,17 @@ static bool TryParseVersion(string content, out byte version)
         using var streamReader = new StreamReader(Request.Body);
         var html = await streamReader.ReadToEndAsync(ct);
         if (!TryParseVersion(html, out var version))
+        {
+            _logger.LogWarning("Failed to parse html crash report version");
             return StatusCode(StatusCodes.Status500InternalServerError);
+        }
 
         if (version <= 13)
             return await _htmlHandlerV13.UploadHtmlAsync(this, ct);
         if (version == 14)
             return await _htmlHandlerV14.UploadHtmlAsync(this, ct);
 
+        _logger.LogWarning("Crash report version is invalid: {CrashReportVersion}", version);
         return StatusCode(StatusCodes.Status500InternalServerError);
     }
 }
\ No newline at end of file