C#

public List<VendorsByProjectAndJobReportEntity> GetVendorsByProjectAndJobReportData(int appCompanyId,
                                                                                    List<int> projectIds, 
                                                                                    List<int> jobIds, 
                                                                                    List<PurchaseOrderType> purchaseOrderTypes)
{
    using (var dc = GetDataContext())
    {
        var results = (from j in dc.Jobs
                        join ac in dc.AppCompanies on j.AppCompanyId equals ac.Id
                        join p in dc.Projects on j.ProjectId equals p.Id
                        join poh in dc.PurchaseOrderHeaders on j.Id equals poh.JobId
                        join cl in dc.CompanyLocations on poh.VendorId equals cl.Id
                        where ac.Id == appCompanyId &&
                                !j.DeletedDT.HasValue &&
                                !p.DeletedDT.HasValue &&
                                (poh.POStatus != (int)PurchaseOrderPOState.Cancelled &&
                                poh.POStatus != (int)PurchaseOrderPOState.Draft)
                        select new VendorsByProjectAndJobReportEntity
                        {
                            ProjectId = p.Id,
                            ProjectInfo = $"{p.ProjectNumber.ToString()} - {p.ProjectName}",
                            JobId = j.Id,
                            JobInfo = $"{j.JobNumber.ToString()} - {j.Phase}",
                            VendorId = cl.Id,
                            VendorName = cl.Location,
                            PurchaseOrderType = (PurchaseOrderType)poh.PurchaseOrderType,
                            PurchaseOrderTotal = poh.Total,
                            ReportTitle = $"{ac.CompanyName} Vendors by Project and Job"
                        }).ToList();

        return results.OrderBy(x => x.ProjectInfo)
                        .ThenBy(x => x.JobInfo)
                        .ThenBy(x => x.PurchaseOrderTypeDesc)
                        .ThenBy(x => x.VendorName).ToList();
    }
}

var predicate = PredicateBuilder.New<VendorsByProjectAndJobReportEntity>();
predicate = predicate.And(x => !x.DeletedDT.HasValue);

WaitIndicatorVisibility = Visibility.Visible;

List<ProjectHeaderEntity> projects = null;
List<NavigationGroupEntity> jobs = null;

await Task.Run(() => { projects = AppCore.BizObject.GetProjectHeaders(AppCore.AppCompany.Id).ToList(); });
await Task.Run(() => { jobs = AppCore.BizObject.GetJobListHeaders(AppCore.AppCompany.Id).ToList(); });

var dialogVm = new VendorsByProjectAndJobReportViewModel(projects, jobs);
DialogResultEx result = DialogService.ShowDialog(dialogVm, typeof(MainWindowView));

WaitIndicatorVisibility = Visibility.Visible;

List<ProjectHeaderEntity> projects = null;
List<NavigationGroupEntity> jobs = null;

List<Task> tasks = new List<Task>();
var t1 = Task.Run(() => { projects = AppCore.BizObject.GetProjectHeaders(AppCore.AppCompany.Id).ToList(); });
var t2 = Task.Run(() => { jobs = AppCore.BizObject.GetJobListHeaders(AppCore.AppCompany.Id).ToList(); });
tasks.Add(t1);
tasks.Add(t2);

await Task.WhenAll(tasks).ConfigureAwait(false);

var dialogVm = new VendorsByProjectAndJobReportViewModel(projects, jobs);
DialogResultEx result = DialogService.ShowDialog(dialogVm, typeof(MainWindowView));

using System;
//using System.Linq;

static class Solution {
static int solution( int[] A ) {

    int flag = 1;
    //A = A.OrderBy(x => x).ToArray();
    Array.Sort(A);

        for (int i = 0; i < A.Length; i++)
        {
            if (A[i] <= 0)
            continue;
        else if (A[i] == flag)
        {
            flag++;
        }
    }
    return flag;
    }
    
    static void Main(string[] args) {
        
    int[] A = { 1, 3, 6, 4, 1, 2 }; 
    //int [] A ={1, 2, 3};
    //int [] A ={-1,-3};

        //var Val = A.Max();
       // if (Val < 1000000) {
        if(A.Length<99999)
        {
        int miss = solution(A);
        Console.Write(miss);       
        }
        else
        {
        Console.WriteLine(" Array is too large! ");
        }
        //}
        //else {
           // Console.WriteLine("Array Values are too big!");
        }
    }

Compiler output:
Compilation failed: 2 error(s), 0 warnings
exec.cs(18,24): error CS0017: Program `exec.exe' has more than one entry point defined: `SolutionWrapper.Main(string[])'
Solution.cs(23,17): error CS0017: Program `exec.exe' has more than one entry point defined: `Solution.Main(string[])'

Quote:

The local function 'Main' is declared but never used

<pre lang="C#"><pre>using System;
using System.Linq;

static int solution(int[] A) {
      int maxSize = 100000;
        int[] counter = new int[maxSize];

        foreach (var number in A)
        {
            if(number >0 && number <= maxSize)
            {
                counter[number - 1] = 1;
            }
        }

        for (int i = 0; i < maxSize; i++)
        {
            if (counter[i] == 0)
                return i + 1;
        }

        return maxSize + 1;    

    static void Main(string[] args) {
        
    int[] A = { 5, 9, 2, 7 };

    Console.WriteLine(solution(A));
    }
}

public async Task<List<Contact>> GetContactsAsync()
{
    return await this.dbContext.Contacts.ToListAsync();
}

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine("Calling Test()");
        Test();
        Console.WriteLine("After Test");

        Console.ReadLine();
    }

    private async static void Test()
    {
        Console.WriteLine("Calling GetSomeData()");
        var results = await GetSomeData();
        Console.WriteLine($"Results: {results}");
    }

    private static Task GetSomeData()
    {
        int x = 0;
        for (; x (x);
    }

    Thread.Sleep(5000);

    return Task.FromResult(x);
}

Calling Test()
Calling GetSomeData()
Results: 900000000
After Test