check the following:

• 
  
• Anonymous access is disabled on workspace site.
  
• Application pool is running under a domain user account with admin permissions on the server.
  
• Grant authinticated users write permissions on the directory C:WINDOWSMicrosoft.NETFrameworkv2.0.50727Temporary ASP.NET Files

Hi Zaccc

Open the workspace web.config file, search for Ldap you shoud see this LDAP:///domain]). At the end of the .com of the domain add :389 The correct string should look like this “LDAP://:domain]:389” Do an IIS reset and workspace should work.

let me know if this helps

Shaun

What is the app pool running as? We typically set up the app pool credentials to be the same as the k2 service.

I put the domain name and port you wrote. But does not work. User is the same everywhere domain administrator.

seidels:

Open the workspace web.config file, search for Ldap you shoud see this LDAP://[domain]). At the end of the .com of the domain add :389 The correct string should look like this “LDAP:///domain]:389” Do an IIS reset and workspace should work.

This is interesting.  I just reconfigured our DEV and TEST servers to fix a problem with reporting services.  We had no problems on our TEST server but we ran into this problem on our DEV server.  I specified the port as suggested and it solved the problem.  I don't understand why, though.  It had been working fine before, and we didn't need to do this on our TEST server.  I have verified that removing it breaks the workspace again.  We are using the same accounts in both environments, so the only thing I can chalk this up to is some wacky Kerberos issue (when in doubt, blame Kerberos ;-)

I am facing similar problem.

I am using same user account on both K2 App Pool in IIS and K2 service.

When I try to open workspace, i get the following error.

You are not authorized to view this page
You do not have permission to view this directory or page using the credentials that you supplied.
--------------------------------------------------------------------------------

Please try the following:

Contact the Web site administrator if you believe you should be able to view this directory or page.
Click the Refresh button to try again with different credentials.
HTTP Error 401.1 - Unauthorized: Access is denied due to invalid credentials.
Internet Information Services (IIS)

Can somebody help me on this?

 @riteshnegi

1) Is this is a new installation?

2) If this is not a new installation, what has changed since it was working?  I would look at domain account settings (you are using domain accounts, right?) and then check the SPNs for the servers (you can find all the information on setting the SPNs correctly in the Getting Started section of the documentation).

3) Is the account a local admin or does it have sufficient permissions to delegate?  Correctly configuring the accounts used for delegation is covered in the Getting Started section of the documentation.

4) Make sure that you are actually using Kerberos for authentication on the site (which you probably are, but worth checking).  See http://support.microsoft.com/kb/215383 on how to set it.

5) Check the permissions on the temporary folder under the ASP.NET 2.0 framework folder.  The easiest thing to do is grant authenticated users full access.

Has anyone found a solution to this problem? We are having similar problems with our installation. Here is our scenario:

1. 
   
2. We have a SharePoint server, a separate K2 server and a separate Database server
   
3. We have a web part on sharepoint site which kicks off workflows on K2 server
   
4. We have Kerberos running

All our stuff was working fine until we applied SSL. Now we are receiving the error mentioned in this forum. There are no errors in the Event Viewer. None of our accounts or SPNs have changed.

 If anyone can help it will be greatly appreciated.

Thanks

I realise that this is an extremely old post, but I have the same error and I am stuck. Can someone please point me in the right direction here?

I had the same issue as the first post that started this thread. I disabled anonymous access in IIS and enabled Kerberos and NTLM authentication in IIS. When I try to open the worspace, i get this error:

You are not authorized to view this page

You do not have permission to view this directory or page using the credentials that you supplied because your Web browser is sending a WWW-Authenticate header field that the Web server is not configured to accept.

Please try the following:

• 
  
• Contact the Web site administrator if you believe you should be able to view this directory or page.
  
• Click the Refresh button to try again with different credentials.

HTTP Error 401.2 - Unauthorized: Access is denied due to server configuration.
Internet Information Services (IIS)

I have managed to sort out the 401 error by adding a new website to IIS and reconfiguring BlackPearl via the configuration manager. But now I am back to the original error:

Error:
Initialization failed: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: indexAn error has occurred.
Please contact your administrator.
Error:
Initialization failed before PreInit: Thread was being aborted.
Possible causes
- using anonymous logon in IIS while Windows security is specified in Workspace configuration
- current logged on user can not be verified against the Active Directory Membership provider
- please review log files for more information

When I run the console mode, I get this error:

C:Program FilesK2 blackpearlHost ServerBin>K2HostServer.exe
;K2 HostServer Console Mode
;======================================
;Loading .NET Framework v2.0.50727
;Framework loaded successfully.
;Creating App Domain.
;Creating Host Server Runtime.
;Boot Strapping Hosting Server Runtime
;Press ESC to end..

Info    1001 Host Server Started as K2-DEVAdministrator
Info    1002 Using .NET Framework v2.0.50727
Info    1003 Host Server Version: 4.8256.1.0
Error   2001 Error Starting Host Server: Object reference not set to an instance
 of an object.
;Error Invoking 'StartHostServer' : Object reference not set to an instance of a
n object.

;Stopped Hosting Server Runtime

C:Program FilesK2 blackpearlHost ServerBin>

Please Please Please HELP.

Hi,

Please go through this blog for help:

http://tssbalak2help.blogspot.com/2015/06/workspace-error.html

Thanks,

Bala