[Typo3] EXT: Last update: "No records found in storage folder!"

[Anders Carlén]

(First of all: Hello to everyone, and a big thank you in advance for the 
patience you are showing to all us new TYPO3 people. I have been reading 
the list archives on the website the last two weeks, and I am impressed 
by your friendliness. And now I dare to ask my (probably stupid) 
question aswell. Please forgive me if this is really easy.)

I am trying to install the EXTENSION: Last update, but after following 
the tutorial I get this error message on my pages:
---
No records found in storage folder!
Warning: Cannot modify header information - headers already sent by 
(output started at 
/usr/local/psa/home/vhosts/operationmission.se/httpsdocs/aron4/typo3conf/ext/lastupdate/pi1/class.tx_lastupdate_pi1.php:187) 
in 
/usr/local/psa/home/vhosts/operationmission.se/httpsdocs/aron4/tslib/class.tslib_fe.php 
on line 2612
---

I don´t understand what is happening, but I have a feeling there is 
something really easy and trivial that I am missing. Can anyone point me 
in the right direction please?

Thank you all,

/anders carlen
sweden