what challenges did Gutenberg face while making the printing press?

Most of the problems that Johannes Gutenberg faced while creating the movable type printing press were financial ones. He frequently struggled to obtain funds for his projects, and it seems that he was not good at handling his finances, as he repeatedly fell into debt.
Gutenberg had nearly bankrupted himself in the 1430s through the failed venture of producing tiny mirrors to sell to pilgrims. With his investors demanding a repayment of their loans, Gutenberg was at a loss of how to repay them. He promised them that he had another lucrative project in the works. This was likely the printing press. It is unclear how he came up with the idea to make a printing press, but we do know that he borrowed money from his sister's husband, Arnold Gelthus, around this time. It is likely that he used this money to fund his invention.
Gutenberg faced more financial hurdles after he took out a further loan, this time from a moneylender named Johan Fust, around 1450. By this time, the printing press had been completed and was in operation. Johannes Gutenberg had embarked on the project of printing Bibles for sale. This venture proved more expensive than Gutenberg had thought, and he had fallen into extreme debt once again. Fust accused Gutenberg of misusing the money and demanded a repayment of his loan. The case was arbitrated in court, which ruled in Fust's favor. The court granted Fust control over Gutenberg's printing workshop and awarded him half of the Bibles printed there. This essentially bankrupted Gutenberg and took away his most lucrative financial venture.