major minor version errors

These types of errors are caused by a Java version mismatch between the compiled proxies and your runtime.

"bad class file. class file has wrong version 50.0, should be 48.0."

Unsupported major.minor version 50.0
JSPG0091E: An error occurred at line: 2 in the file: /login.jsp
JSPG0093E: Generated servlet error from file: /login.jsp

Below are a list of some of the version numbers and their corresponding Java runtimes:
Version 50.0 = Java 1.6.x
Version 49.0 = Java 1.5.x
Version 48.0 = Java 1.4.x

The server is expecting 48.0 version of the code, meaning, code built with 1.4.x version of jvm, but, the supplied code was built against version 50.0 meaning 1.6.x version of the jvm.

What one can do to solve this is, if you use RAD kind of tools to build the code, configure build path to have appropriate JRE, clean your builds and re build.

uptime

uptime is a measure of the time a machine has up been.
This is pretty useful command.

To know since when the system is up one can do like this at the terminal prompt
$uptime
11:10:27 up 9 mins, 2 users, Load average: 0.02, 0.24, 0.18

Determining system uptime in windows -

1.

C:\> systeminfo | find "Time:"
System Up Time:            0 Days, 8 Hours, 7 Minutes, 19 Seconds

Note: Windows Vista Business 64-bit and Windows 7 do not return a "System Up Time" but "System Boot Time" instead.

2.

C:\> net statistics server | find "since"
Server Statistics for \\COMPUTERNAME
 
Statistics since 8/31/2009 8:52:29 PM