Check the logs
The Application Server can record a variety of useful information in different log files. The value of these log files in detecting and troubleshooting any problems is immeasurable. Many times, application users will not report what they presume to be minor errors, or they may not even be aware of something like a missing image which, if present, would enhance the usability or appearance of the application.
The primary server log is the Access log. This file contains an entry for every resource that was requested and, along with other information, an HTTP status code to indicate the result of the request. A regular review of the Access log with reveal any recurring problems, such as missing files (status code 404) or pages that generally generate errors (typically status code 500).
The Error log also records each error, and usually contains some more specific information on what the problem was. For example, the Access log may record that a specific request resulted in a 500 status, while the corresponding entry in the Error log may reveal that it was an Xbasic error, with the specific error text and line number.
The Xbasic Error Stack log records the execution stack any time an Xbasic error occurs. This means that it will not record anything for a non-Xbasic error such as if a file is not found. When there is an Xbasic error, additional information about the execution state of your code will be logged. During normal operation this log will have nothing to record, so it is recommended that this log be left enabled in order to capture as much debugging information as possible in the event an error does occur.
The Raw HTTP Traffic log records the raw data sent on the connection between the server and the client. The information in this log can be used to verify that the server is receiving a complete request as expected and sending a proper response to the client. This generally results in a large amount of data being logged very quickly, and it potentially saves sensitive data in an unencrypted format, so it is best not to enable this log unless a specific error condition is being debugged.