Are you using the Package Manager Console?

Then make sure you have the corrent project selected (in Default Project field/box), where you have Episerver.Forms module is already installed .

Again, check in Consolidate tab (in Manage Nuget Package for solution), if you have multiple versions of Episerver.Forms get installed. If yes then correct that.

EPiServer.Forms.Samples is dependent of Episerver.Forms, and mudule version mismatch (or installed multiple different version) may cause that issue. So, make sure you have same version installed in all the projects and also you have EPiserver.Forms installed in the project where you are trying to install/upgrade the Episerver.Forms.Sample

Thanks Praful for the information. The version of Episerver.forms installed is 4.30.2.0 and project has reference for the same.

An older version was there, which I removed from packages folder. Still getting below error:

Install failed. Rolling back...

Package 'EPiServer.Forms.Samples.3.7.0 : EPiServer.Forms [4.30.1, 5.0.0)' does not exist in project 'Aspect.Web'

Please suggest.

Try clearing nuget cache and then try to install again. Can you also paste here packages.config if solution not work.

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="BVN.404Handler" version="11.4.0" targetFramework="net48" />
  <package id="Castle.Core" version="4.4.1" targetFramework="net48" />
  <package id="Castle.Windsor" version="4.1.1" targetFramework="net48" />
  <package id="DotNetZip" version="1.10.1" targetFramework="net462" />
  <package id="elmah" version="1.2.2" targetFramework="net462" />
  <package id="Elmah.AzureTableStorage" version="1.0.0.0" targetFramework="net462" />
  <package id="elmah.corelibrary" version="1.2.2" targetFramework="net462" />
  <package id="Elmah.Mvc" version="2.1.2" targetFramework="net462" />
  <package id="EntityFramework" version="6.4.4" targetFramework="net48" />
  <package id="EPiServer.AddOns.Helpers" version="0.4.0.0" targetFramework="net48" />
  <package id="EPiServer.Azure" version="10.0.1" targetFramework="net48" />
  <package id="EPiServer.CMS" version="11.20.3" targetFramework="net48" />
  <package id="EPiServer.Cms.AddOns.Blocks" version="2.4.1" targetFramework="net48" />
  <package id="EPiServer.CMS.AspNet" version="11.20.3" targetFramework="net48" />
  <package id="EPiServer.CMS.Core" version="11.20.3" targetFramework="net48" />
  <package id="EPiServer.CMS.TinyMce" version="2.13.2" targetFramework="net48" />
  <package id="EPiServer.CMS.UI" version="11.32.1" targetFramework="net48" />
  <package id="EPiServer.CMS.UI.Core" version="11.32.1" targetFramework="net48" />
  <package id="EPiServer.Find" version="13.3.0" targetFramework="net48" />
  <package id="EPiServer.Find.Cms" version="13.3.0" targetFramework="net48" />
  <package id="EPiServer.Find.Framework" version="13.3.0" targetFramework="net48" />
  <package id="EPiServer.Forms" version="4.30.2" targetFramework="net48" />
  <package id="EPiServer.Forms.Core" version="4.30.2" targetFramework="net48" />
  <package id="EPiServer.Forms.Samples" version="3.3.0" targetFramework="net48" />
  <package id="EPiServer.Forms.UI" version="4.30.2" targetFramework="net48" />
  <package id="EPiServer.Framework" version="11.20.3" targetFramework="net48" />
  <package id="EPiServer.Framework.AspNet" version="11.20.3" targetFramework="net48" />
  <package id="EPiServer.Labs.LanguageManager" version="4.0.1" targetFramework="net48" />
  <package id="EPiServer.Logging.Log4Net" version="2.2.2" targetFramework="net48" />
  <package id="EPiServer.Marketing.KPI" version="2.5.4" targetFramework="net48" />
  <package id="EPiServer.Marketing.Messaging" version="1.3.0" targetFramework="net48" />
  <package id="EPiServer.Marketing.Testing" version="2.6.5" targetFramework="net48" />
  <package id="EPiServer.Packaging" version="3.4.0" targetFramework="net48" />
  <package id="EPiServer.Packaging.UI" version="3.3.0" targetFramework="net462" />
  <package id="EPiServer.Search" version="9.0.3" targetFramework="net48" />
  <package id="EPiServer.ServiceLocation.StructureMap" version="2.0.3" targetFramework="net48" />
  <package id="EPiServer.TinyMCESpellChecker" version="2.0.0" targetFramework="net48" />
  <package id="EPiServer.VisitorGroupsCriteriaPack" version="2.0.1" targetFramework="net48" />
  <package id="EPiServer.XForms" version="1.0.3" targetFramework="net48" />
  <package id="Geta.404Handler" version="1.2.1" targetFramework="net48" />
  <package id="lodash.TypeScript.DefinitelyTyped" version="2.4.9" targetFramework="net462" />
  <package id="log4net" version="2.0.8" targetFramework="net462" />
  <package id="Lucene.Net" version="3.0.3" targetFramework="net48" />
  <package id="Microsoft.AspNet.Mvc" version="5.2.7" targetFramework="net48" />
  <package id="Microsoft.AspNet.Providers.Core" version="2.0.0" targetFramework="net462" />
  <package id="Microsoft.AspNet.Razor" version="3.2.7" targetFramework="net48" />
  <package id="Microsoft.AspNet.WebApi" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebApi.Client" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebApi.Core" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebApi.WebHost" version="5.2.3" targetFramework="net462" />
  <package id="Microsoft.AspNet.WebPages" version="3.2.7" targetFramework="net48" />
  <package id="Microsoft.Azure.KeyVault.Core" version="1.0.0" targetFramework="net462" />
  <package id="Microsoft.Azure.Services.AppAuthentication" version="1.6.0" targetFramework="net48" />
  <package id="Microsoft.Data.Edm" version="5.6.4" targetFramework="net45" />
  <package id="Microsoft.Data.OData" version="5.6.4" targetFramework="net45" />
  <package id="Microsoft.Data.Services.Client" version="5.6.4" targetFramework="net45" />
  <package id="Microsoft.IdentityModel.Clients.ActiveDirectory" version="5.2.8" targetFramework="net48" />
  <package id="Microsoft.IdentityModel.JsonWebTokens" version="6.8.0" targetFramework="net48" />
  <package id="Microsoft.IdentityModel.Logging" version="6.8.0" targetFramework="net48" />
  <package id="Microsoft.IdentityModel.Tokens" version="6.8.0" targetFramework="net48" />
  <package id="Microsoft.Net.Compilers" version="2.2.0" targetFramework="net462" developmentDependency="true" />
  <package id="Microsoft.Net.Http" version="2.0.20710.0" targetFramework="net45" />
  <package id="Microsoft.Rest.ClientRuntime" version="2.3.22" targetFramework="net48" />
  <package id="Microsoft.Tpl.Dataflow" version="4.5.24" targetFramework="net462" />
  <package id="Microsoft.Web.Infrastructure" version="1.0.0.0" targetFramework="net462" />
  <package id="Microsoft.Web.Xdt" version="2.1.1" targetFramework="net462" />
  <package id="Microsoft.WindowsAzure.ConfigurationManager" version="3.1.0" targetFramework="net462" />
  <package id="Mogul.SEO.Manager.Package" version="5.2.5.0" targetFramework="net48" />
  <package id="Newtonsoft.Json" version="12.0.3" targetFramework="net48" />
  <package id="NHunspell" version="1.2.5359.26126" targetFramework="net462" />
  <package id="NuGet.Core" version="2.7.2" targetFramework="net462" />
  <package id="React.TypeScript.DefinitelyTyped" version="0.1.12" targetFramework="net462" />
  <package id="SharpZipLib" version="0.86.0" targetFramework="net462" />
  <package id="StructureMap" version="4.7.1" targetFramework="net48" />
  <package id="structuremap.web" version="4.0.0.315" targetFramework="net48" />
  <package id="structuremap.web-signed" version="3.1.6.191" targetFramework="net462" />
  <package id="structuremap-signed" version="3.1.9.463" targetFramework="net462" />
  <package id="System.ComponentModel.Annotations" version="4.7.0" targetFramework="net48" />
  <package id="System.Data.SqlClient" version="4.8.2" targetFramework="net48" />
  <package id="System.IdentityModel.Tokens.Jwt" version="6.8.0" targetFramework="net48" />
  <package id="System.IO" version="4.3.0" targetFramework="net48" />
  <package id="System.Net.Http" version="4.3.4" targetFramework="net48" />
  <package id="System.Reflection.Emit" version="4.7.0" targetFramework="net48" />
  <package id="System.Reflection.Emit.Lightweight" version="4.3.0" targetFramework="net462" />
  <package id="System.Runtime" version="4.3.1" targetFramework="net48" />
  <package id="System.Security.AccessControl" version="4.7.0" targetFramework="net48" />
  <package id="System.Security.Cryptography.Algorithms" version="4.3.1" targetFramework="net48" />
  <package id="System.Security.Cryptography.Encoding" version="4.3.0" targetFramework="net48" />
  <package id="System.Security.Cryptography.Primitives" version="4.3.0" targetFramework="net48" />
  <package id="System.Security.Cryptography.X509Certificates" version="4.3.2" targetFramework="net48" />
  <package id="System.Security.Cryptography.Xml" version="4.7.0" targetFramework="net48" />
  <package id="System.Security.Permissions" version="4.7.0" targetFramework="net48" />
  <package id="System.Security.Principal.Windows" version="4.7.0" targetFramework="net48" />
  <package id="System.Spatial" version="5.6.4" targetFramework="net45" />
  <package id="System.Threading.AccessControl" version="4.7.0" targetFramework="net48" />
  <package id="System.ValueTuple" version="4.5.0" targetFramework="net48" />
  <package id="WindowsAzure.ServiceBus" version="6.0.3" targetFramework="net48" />
  <package id="WindowsAzure.Storage" version="9.3.3" targetFramework="net48" />
</packages>