Removed empty string null middleware as was causing issues

app/Http/Kernel.php

@@ -15,7 +15,6 @@ class Kernel extends HttpKernel
         \Illuminate\Foundation\Http\Middleware\CheckForMaintenanceMode::class,
         \Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,
         \BookStack\Http\Middleware\TrimStrings::class,
-        \Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
     ];
 
     /**

app/Http/Middleware/TrimStrings.php

@@ -14,5 +14,6 @@ class TrimStrings extends BaseTrimmer
     protected $except = [
         'password',
         'password_confirmation',
+        'password-confirm',
     ];
 }