Excel Web Access(An error has occurred.Please contact your system administrator if this problem persists. )

Question

I'm using share point 2007 under windows server 2008 R2(one web server, another db server).When I publish a excel(*.xlsx) to report library or view it in web browser with the same error as bellows:
Excel Web Access
An error has occurred.
Please contact your system administrator if this problem persists.
Please kindly support to guide how to fix it with bellow information in details such as log.Many thanks!
1. The 12/logs file is as bellows:
10/10/2014 09:53:55.18  w3wp.exe (0x6528)                        0x5C08 Excel Services               
 Excel Calculation Services     2u7d Medium   ExcelServerSharedWebApplication.Local: An exception was thrown by configdb infrastructure: System.InvalidOperationException: ExcelServerSharedWebApplication.Local: Could
not get ServerContext.Current, which indicates that either SharePoint or the SSP infrastructure isn't provisioned correctly or that we're running outside of a web context.     at Microsoft.Office.Excel.Server.ExcelServerSharedWebApplication.get_Local(). 
10/10/2014 09:53:55.18  w3wp.exe (0x6528)                        0x5C08 Excel Services               
 Excel Services Administration  8tqh Critical Excel Services: Unexpected exception while trying to access Shared Services Database;. Error = ExcelServerSharedWebApplication.Local: Could not get ServerContext.Current, which indicates that
either SharePoint or the SSP infrastructure isn't provisioned correctly or that we're running outside of a web context.. 
10/10/2014 09:53:55.18  w3wp.exe (0x6528)                        0x5C08 Excel Services               
 Excel Web Access               6nfi Unexpected InternalEwr.OpenWorkbook - An unexpected exception in the ECS Proxy occurred. Message: Microsoft.Office.Excel.Server.ExcelServerSettingException:
An error has occurred. ---> System.InvalidOperationException: ExcelServerSharedWebApplication.Local: Could not get ServerContext.Current, which indicates that either SharePoint or the SSP infrastructure isn't provisioned correctly or that we're running
outside of a web context.     at Microsoft.Office.Excel.Server.ExcelServerSharedWebApplication.get_Local()     --- End of inner exception stack trace ---     at Microsoft.Office.Excel.Server.ExcelServerSharedWebApplication.get_Local()    
at Microsoft.Office.Excel.Server.ExcelServerSettings.get_Settings()     at Microsoft.Office.Excel.Server.ExcelServerSettings.get_EcsList()     at Microsoft.Office... 
2.the event in event viewer is:
Log Name:      Security
Source:        Microsoft-Windows-Security-Auditing
Date:          2014/10/10 9:49:43
Event ID:      4625
Task Category: Logon
Level:         Information
Keywords:      Audit Failure
User:          N/A
Computer:      ***.net
Description:
An account failed to log on.
Subject:
 Security ID:  NULL SID
 Account Name:  -
 Account Domain:  -
 Logon ID:  0x0
Logon Type:   3
Account For Which Logon Failed:
 Security ID:  NULL SID
 Account Name:  ***
 Account Domain:  ***
Failure Information:
 Failure Reason:  An Error occured during Logon.
 Status:   0xc000006d
 Sub Status:  0x0
Process Information:
 Caller Process ID: 0x0
 Caller Process Name: -
Network Information:
 Workstation Name: ***
 Source Network Address: ***
 Source Port:  63664
Detailed Authentication Information:
 Logon Process:  
 Authentication Package: NTLM
 Transited Services: -
 Package Name (NTLM only): -
 Key Length:  0
This event is generated when a logon request fails. It is generated on the computer where access was attempted.
The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe.
The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network).
The Process Information fields indicate which account and process on the system requested the logon.
The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.
The authentication information fields provide detailed information about this specific logon request.
 - Transited services indicate which intermediate services have participated in this logon request.
 - Package name indicates which sub-protocol was used among the NTLM protocols.
 - Key length indicates the length of the generated session key. This will be 0 if no session key was requested.
Event Xml:
<Event xmlns="">
  <System>
    <Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" />
    <EventID>4625</EventID>
    <Version>0</Version>
    <Level>0</Level>
    <Task>12544</Task>
    <Opcode>0</Opcode>
    <Keywords>0x8010000000000000</Keywords>
    <TimeCreated SystemTime="2014-10-10T01:49:43.563436300Z" />
    <EventRecordID>37602685</EventRecordID>
    <Correlation />
    <Execution ProcessID="532" ThreadID="26096" />
    <Channel>Security</Channel>
    <Computer>***.net</Computer>
    <Security />
  </System>
  <EventData>
    <Data Name="SubjectUserSid">S-1-0-0</Data>
    <Data Name="SubjectUserName">-</Data>
    <Data Name="SubjectDomainName">-</Data>
    <Data Name="SubjectLogonId">0x0</Data>
    <Data Name="TargetUserSid">S-1-0-0</Data>
    <Data Name="TargetUserName">***</Data>
    <Data Name="TargetDomainName">***</Data>
    <Data Name="Status">0xc000006d</Data>
    <Data Name="FailureReason">%%2304</Data>
    <Data Name="SubStatus">0x0</Data>
    <Data Name="LogonType">3</Data>
    <Data Name="LogonProcessName">
    </Data>
    <Data Name="AuthenticationPackageName">NTLM</Data>
    <Data Name="WorkstationName">***</Data>
    <Data Name="TransmittedServices">-</Data>
    <Data Name="LmPackageName">-</Data>
    <Data Name="KeyLength">0</Data>
    <Data Name="ProcessId">0x0</Data>
    <Data Name="ProcessName">-</Data>
    <Data Name="IpAddress">***</Data>
    <Data Name="IpPort">63664</Data>
  </EventData>
</Event>

Answer 1

Hi Tracy,
Have you changed something on your SharePoint 2007 environment recently before this issue occurred?
This issue may be related to Alternate Access Mappings settings like the following similar post, if you have configured AAM, you can check if this issue happened to some URLs, if it's the case, please add the problematic URLs as a Publish URLs for the default
zone for your web application, and also add these URLs as trusted locations, then check results again.
If above doesn't work, please enable ULS log on verbose level to get more useful log errors which time are corresponding to the errors occur. 
https://social.technet.microsoft.com/Forums/en-US/c9ab4818-65c9-444d-be50-1bfed1f1509b/excel-web-access-web-part-works-on-intranet-but-not-internet?forum=sharepointgenerallegacy
http://blog.bugrapostaci.com/2011/09/08/how-to-enable-verbose-log-mode-on-moss-2007/
Thanks
Daniel Yang
TechNet Community Support