Can anyone explain what is wrong with my text? how to fix it? 

Never seen this before - is it with all fonts? Can´t see any unusual setting in the screenshot but Status bar is missing - try to reset Preferences - shut down Inkscape and restart.

Your text has a dotted stroke (probably one you have used before in other work). Remove it.

Polygon

Can´t see any unusual setting in the screenshot but Status bar is missing - try to reset Preferences - shut down Inkscape and restart.

I did, it didn't help 

zerocinquanta

Your text has a dotted stroke (probably one you have used before in other work). Remove it.

Yes, you are right. Thank you)))) 

Haha - same "issue" than here: https://inkscape.org/forums/beyond/text-looks-odd/#c32078

That´s why the bottom of the Inkscape window is so important for screenshots.