No one besides Cotten knew the passkeys for the cold wallet.
Sky News reports that QuadrigaCX's founder, Gerald Cotton's death means the company can not repay $190m (£110m) to clients. The cryptocurrencies the exchange dealt with were bitcoin, bitcoin gold, bitcoin cash, bitcoin cash SV, litecoin and ether.
Ms Robertson said she was not involved in Mr Cotten's business while he was alive and did not know the password or recovery key. The mysterious circumstances also gave rise to theories that Cotten hadn't actually died (though Robertson included his death certificate with the affidavit), and at least one payment processing firm holding some of the company's cash funds disputed the amount attributed to it in the affidavit.
The company's board is, however, expected to appoint Ernst & Young to oversee the proceedings.
"Unfortunately, these efforts have not been successful", the statement added.
The 30-year-old man died suddenly of complications with Crohn's disease in early December while doing philanthropic work in India.
The founder of a currency exchange in Canada who unexpectedly died last December appears to have taken the company's access to its encrypted funds with him.
The time period can be extended by the court if QuadrigaCX is able to demonstrate that it will likely file a Plan of Arrangement and the extension is not damaging to creditors.
The debt filing comes weeks after Robertson announced that Cotten had died - an event she described as "a shock to all of us".
Quadriga's "cold wallets" contain inaccessible assets belonging to around 115,000 customers, according to Robertson's court filings.
Then came last week's revelation that QuadrigaCX owes more than $100 million worth of cryptocurrency to its customers but is unable to repay because Cotten had sole control of the private keys connected to those funds. "Despite repeated and diligent searches, I have not been able to find them written down anywhere", she writes. Experts, meanwhile, were only met with "limited success" in their attempt to hack into the encryption.
All we can say for certain right now is people don't have their money, and they're very unhappy.
Robertson says that she has received online threats as a result of the weird deadlock.
A number of web-based conspiracies have been speculated on forums such as Reddit about the locked up cryptocurrency, and Robertson claims she has received a number of threats since Cotten's death. The document showed Quadriga has $30 million in bank drafts, many of which it has had trouble depositing.