The blinking inscription that appears from time to time in the window of the game client is a part of the so called «antimacrossystem». It is a defense against unfair players who improve their skills by using a special program making simple actions (extraction and melting of ore, etc.)
When you do something in the game, the antimacros counter increases. When it reaches 100 scores, there appears an inscription that you should type as a confirmation that you do not use a program for «pumping прокачки». In this way you will null the counter. You can also invoke this inscription at any time yourself by pressing F11.
If you do not enter this inscription you will not be able to do many actions, the experience scores of the character will not increase and you can not improve your skills.