IdentityServer4 {"error":"invalid_client"} - authentication

Question

I am using IdentityServer4 (version 3.0.2.0) and facing no client id issue. The exact error is
ERROR| No client with id 'myclientId' found. aborting
Startup.cs of IdentityServer4 project
services.AddIdentityServer()
.AddDeveloperSigningCredential()
// .AddInMemoryCaching()
.AddInMemoryApiResources(Configuration.GetSection("IdentityServer:ApiResources"))
.AddInMemoryClients(Configuration.GetSection("IdentityServer:Clients"))
.AddOperationalStore(options =>
{
options.ConfigureDbContext = builder =>
builder.UseSqlServer(connectionString,
sql => sql.MigrationsAssembly(migrationsAssembly));
// this enables automatic token cleanup. this is optional.
options.EnableTokenCleanup = Convert.ToBoolean(Configuration["CleanUp:IsEnabled"]);
options.TokenCleanupInterval = Convert.ToInt32(Configuration["CleanUp:Interval"]); // interval in seconds
});
Also, I have sha256 converted client_secret in appsettings.json file, sample appsettings.json
"IdentityServer": {
"ApiResources": [
{
"Name": "myapi",
"DisplayName": "my api",
"Scopes": [
{
"Name": "mycustomscope"
},
{
"Name": "openid"
}
],
"ApiSecrets": [
{
"Value": "my sha256 converted secret string",
"Description": "my api"
}
]
}
],
"Clients": [
{
"Enabled": true,
"ClientId": "myclientId",
"AccessTokenLifetime": 100000000,
"ProtocolType": "oidc",
"RequireClientSecret": true,
"IdentityTokenLifetime": 300,
"AuthorizationCodeLifetime": 300,
"ConsentLifetime": 300,
"AbsoluteRefreshTokenLifetime": 2592000,
"SlidingRefreshTokenLifetime": 1296000,
"RefreshTokenExpiration": true,
"AlwaysSendClientClaims": false,
"ClientName": "myclientId",
"ClientSecrets": [
{
"Value": "my sha256 converted secret string",
"Type": "SharedSecret"
}
],
"AllowedGrantTypes": [ "client_credentials", "password" ],
"AllowedScopes": [ "mycustomscope", "openid" ],
"RequireConsent": true
}
]
}
Sample token request from postman/JMeter
url: https://myip:port/myappPool/connect/token
method type: POST
Parameters are:
{
"client_id":"myclientId",
"client_secret": "plaintext secret",
"username":"abcdefghijkl",
"scope":"mycustomscope",
"device_id":"custom property",
"password": "mypassword",
"grant_type":"password",
"app_version":"custom property",
"hashed_value":"custom property"
}

Answer 1

I am posting answer to my own question because I have solved the issue. For me below given field was making an issue. After removing this field, the code ran just fine.
"RefreshTokenExpiration": true
Turns out, IdentityServer4.Models.Client does not have any boolean field named RefreshTokenExpiration but class object.