According to Bitcoin news site CoinShark, TON project`s team of developers is about to switch all of the validators off at the end of July, thus they are going to cease the test network support.
Be sure to save data
Pavel Durov and his team applied to third-party developers asking to stop testing the TON network as well as to keep important information.
Starting your network is possible
The developers claimed, if anyone wants to maintain the testing, they are able to open their validators.
We are discontinuing our support of the test network of the TON Blockchain. If you need to continue testing after this date, you can install your own testnet validators as explained
TON Cessation
Pavel Durov had no other way but to close the TON project because of troubles with SEC, he also returned $1.2 billion to investors and paid $18.5 million fine.
Source: https://railsonwave.it/ton-developers-are-going-to-disable-the-validators-on-august-1-2020/