Susquehanna-backed BlockFills is preparing for restructuring and battling a customer lawsuit after acknowledging financial losses and accounting lapses, becoming one of the first firms to fall victim to the recent downturn in crypto markets.

The Chicago-based crypto options and lending platform has sought restructuring advice from consulting firm BRG and lawyers Katten Muchin Rosenman, according to people familiar with the matter.

The firm last month was forced to freeze client withdrawals following loan losses and bad bets on crypto mining. BlockFills has since told potential new investors that it previously suffered from inaccuracies in its financial reporting.

Trouble at the firm evokes echoes of the litany of issues that befell…