We are having an ASA 5510 in routed mode.Now I can telnet the ASA.But when I log on by Cisco ASDM launcher and try to check the configuration, it is saying"ASDM is unabale to load the configuarion ,please check your configuration and connectivity".Please advice ..
In ASDM, clear ASDM cache and internal log buffer (nothing to do with firewall config or logs) and then select refresh ASDM with the running configuration on the device option. all these options are there in the file menu of ASDM.
This will help you to run ASDM in all the JAVA versions. You might not want to change the JAVA version just for one application, other apps may want to use the latest one.
If you still face issues,
1) Find the asdm-launcher.config file (C:\Program Files\Cisco Systems\ASDM\asdm-launcher.config)
2) Right click, choose properties and remove the 'read only' check
3) Open the file and add the following line:
javapath c:\Program Files\Java\jre1.6.0_07\bin\client\jvm.dll
4) Save the file and replace the read only check
Kindly let me know if this works for you.