TNS-12541: TNS:no listener

The command lsnrctl start ORCLPLSQL resulted in "TNS-12541:TNS:no listener " error yesterday; I was puzzled (See below).

(Screen -01)

Oracle was working perfectly fine till then; moreover, I had not installed any new s/w at all.What could then be the issue?
A search on Google brought up this page: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor

As listed in that web page, I tried the first one.
The Command, show parameter local listener displayed that tns port has not changed, listener.ora is pointing to the correct port.
Next, I tried tnsping avs.ramanujam.com, which resulted in the same error message.

(Screen -02)

Another thing I noticed was, both starting up the listener and tnsping was taking more time than usual. Next I ran the ifconfig command, I noticed that the ipaddress had changed. (I have to make a confession here. Even though the best practices and the recommendation is that "servers" should have static ipaddress, I had not made it static.) Bang- sound of myself hitting my head  -changed the ipaddress in the /etc/hosts and I was back into business in no matter of time.
Final screen is after successful connection is shown below

(Screen -03)

SO Exception, TNS-12514 and other errors

My Windows 7 was giving troubles of late and was crashing (Blue-screen-of-death) almost 3/4 times daily (Need to figure out that one at some other point of time). Naturally, the Linux OS installed in the VMware, also started giving problems. For the last two days, I could not connect to Oracle from SQLDeveloper. First I got ORA-12541 (Screen -1), then, ORA-12514 error and lastly, a "SO Exception".

Screen -01

Lastly, I logged into SQLPLUS as sys and ran the following command:-
Show parameter local listener (Screen -02).

Screen -02

Bingo! I found that the port number was wrong. Instead of 25000,my tnsnames and listener was set at 3801. Modified the listener.ora and tnsnames.ora and SQLDeveloper was able to connect again (Screen -03)

Screen -03

REP-1219 error;object; has no size

Most of the times you face the error, you generally delete the object.
This error occurs when you create a report in bitmap mode and run it as a character report.

Solution is as below:
Open reports builder and the rdf file which is giving error

1. Go to FILE -> ADMINISTRATION -> CONVERT
2. A dialog box will popup.
3. In OPTIONS tab, select DESTINATION UNIT as CHARACTER, and select OVERWRITE as NEWNAME
4. Then in CONVERSION tab select the following
Document Type : Report
Source Type : rdf
Source : It is the file for which you are getting error
Destination Type : rdf
Destination : give the location and filename for the destination file
3. Then click on OK
Reopen the rdf file, the error is no longer reported.