cannot install vsphere webclient

Hi!

We installed vcenter simple and now, we cannot install vsphere webclient. When we asked to enter credentials admin@System-Domain, we get an error that are invalidad credentials (the provider credentials are not vaild....). Below I show the log:

ERROR com.vmware.vim.sso.client.impl.SoapBindingImpl] SOAP fault
javax.xml.ws.soap.SOAPFaultException: Authentication failed
    at com.sun.xml.internal.ws.fault.SOAP11Fault.getProtocolException(SOAP11Fault.java:178)
    at com.sun.xml.internal.ws.fault.SOAPFaultBuilder.createException(SOAPFaultBuilder.java:111)
    at com.sun.xml.internal.ws.client.dispatch.DispatchImpl.doInvoke(DispatchImpl.java:176)
    at com.sun.xml.internal.ws.client.dispatch.DispatchImpl.invoke(DispatchImpl.java:195)
    at com.vmware.vim.sso.client.impl.SoapBindingImpl.sendMessage(SoapBindingImpl.java:131)
    at com.vmware.vim.sso.client.impl.SoapBindingImpl.sendMessage(SoapBindingImpl.java:82)
    at com.vmware.vim.sso.client.impl.SecurityTokenServiceImpl$RequestResponseProcessor.sendRequest(SecurityTokenServiceImpl.java:674)
    at com.vmware.vim.sso.client.impl.SecurityTokenServiceImpl$RequestResponseProcessor.executeRoundtrip(SecurityTokenServiceImpl.java:608)
    at com.vmware.vim.sso.client.impl.SecurityTokenServiceImpl.acquireToken(SecurityTokenServiceImpl.java:118)
    at com.vmware.vim.install.impl.RegistrationProviderImpl.acquireSamlToken(RegistrationProviderImpl.java:524)
    at com.vmware.vim.install.impl.RegistrationProviderImpl.initialize(RegistrationProviderImpl.java:253)
    at com.vmware.vim.install.impl.RegistrationProviderImpl.<init>(RegistrationProviderImpl.java:133)
    at com.vmware.vim.install.RegistrationProviderFactory.getRegistrationProvider(RegistrationProviderFactory.java:143)
    at com.vmware.vim.install.RegistrationProviderFactory.getRegistrationProvider(RegistrationProviderFactory.java:60)
    at com.vmware.vim.install.cli.commands.CommandArgumentsParser.createServiceProvider(CommandArgumentsParser.java:253)
    at com.vmware.vim.install.cli.commands.CommandArgumentsParser.parseCommand(CommandArgumentsParser.java:99)
    at com.vmware.vim.install.cli.commands.CommandFactory.createValidateLsCommand(CommandFactory.java:36)
    at com.vmware.vim.install.cli.RegTool.process(RegTool.java:86)
    at com.vmware.vim.install.cli.RegTool.main(RegTool.java:33)

DEBUG com.vmware.vim.install.impl.RegistrationProviderImpl] Provided credentials are not valid.
ERROR com.vmware.vim.install.cli.commands.CommandArgumentsParser] Cannot authenticate user
INFO  com.vmware.vim.install.cli.RegTool] Return code is: InvalidCredentials

I think that the password is correct
Could Install with another user? how to reset password of admin@system-domain?

thanks!