After the unit stopped issuing social security for no reason, now the boss runs away and takes away the official seal and other materials. How to cancel the formalities?

This is a fast knot. According to the regulations, you can only submit an arbitration application to the local labor arbitration commission, demanding compensation for losses, payment of social security funds and termination of the labor contract. But the problem is that if you can't find the person in charge of the company, there is likely to be a need for publicity. If this is delayed for several months, there will be no money and the problem will not be solved.

Of course, if the company still has some money, you can consider submitting it to labor dispute arbitration on the one hand, and actively seeking the assistance of the obligee on the other hand, and asking the person who has the right to dispose of it to liquidate the company.