Samdani is correct.Try assembling using runAssembler with MD5 option, perhaps alogirthm might match with the updated db entry of admin/admin.
As mentioned in above posts the hashing algorithm is changed in 10.1+
Earlier it was MD5 encryption but now sha-1 is used. The link you are following to reset the password works for the md5 not sha-1.
As karthik mentioned ,to make the resolution suggested in the link work for your application you need to add following to your run-assembler :
<arg value="-layer" />
<arg value="md5" />
Edited by: Waste Ideas on Feb 18, 2013 1:12 AM
Also if you are using build scripts to assemble your modules you can configure this value there. Just find the below line:
<target name="execute-assembler-cmd" description="Executes ATG's runAssembler by command line call">
and add one line below this:
<property name="assemble.cmd.layers" value="md5" />
It will work.
Also If you dont want to use -layer md5:
1) Delete DAS_ACCOUNTS Table data,Take back up before deleting.
2) Build application w/o md5 option.
3) Start server.
FYI-at first run automatically accoutns are created.