Kaseya Logon fails with either an unidentified ASP error or the error "The HTTP headers are already written to the client browser. Any HTTP header modifications must be made before writing page content."
This is caused by an issue with the way that some browsers interpret a line in the AuthAnvil.asp file during Kaseya logon.
Open up the AuthAnvil.asp file (c:\kaseya\WebPages\AuthAnvil\inc\AuthAnvil.asp) and on or around line 469, comment out the line by adding a pair of slashes in front of it, so that it reads //Response.Cookies("sessionId") = -1; and save the file.
AuthAnvil Addin for Kaseya 1.0, AuthAnvil Kaseya Logon Agent 1.5.x
If you have any questions or need some help, we would be happy to assist. Open a case at kaseya.zendesk.com .