Hey Aleksei4ik, we can't allow advertising of JSE for sale in the official channels I'm afraid.

Kambas, could you check https://load.jsecoincom and see if anything is blocking it?
Could be a websockets issue as well. If you are using chrome try opening the web developer console with CTRL + SHIFT + J and seeing if there are any errors when clicking the mining button. (CTRL + SHIFT + K in Firefox).