Production on Tesla’s highly-anticipated solar roof tiles is currently stalled due to aesthetic quality concerns and assembly-line problems at its Buffalo, New York, factory, according to Reuters. In an article published last week, Reuters interviewed eight former and current employees at Tesla, Inc. and their joint venture partner Panasonic, who revealed that the future of solar tile production is murky at this time. According to Reuters’s unnamed sources, since opening last year, manufacturing at Tesla’s Gigafactory 2 in Buffalo has suffered repeated interruptions with equipment issues and delays in achieving the tile style CEO Elon Musk is seeking. The state-owned, photovoltaic cell factory, leased by Tesla’s subsidiary SolarCity, currently employs around 600 people. After the prototypes of Musk’s sun-powered roof tiles were revealed two years ago, U.S. customers put down $1,000 deposits and production ramped up at the facility. Tesla told Reuters in a statement that though production has slowed, work can be expected to increase later this year. “We are steadily ramping up Solar Roof production in Buffalo and are also continuing to iterate on the product design and production process,” Tesla said. “We plan to ramp production more toward the end of 2018.” Per the subsidy agreement that allowed Tesla to build the $350 million factory and purchase production equipment, the company has to live up to its investment and employment promises in Buffalo and beyond. New York lawmakers are skeptical that the company can achieve the mandates the state and the company have set. At least 1,460 people must be employed by Tesla within the first two years of opening, and the company must spend $5 billion in New York over the next ten years. Panasonic employees told Reuters that their current production on solar products has been delayed as well, but it’s due to pick back up in September. The company has also started selling to outside buyers since Tesla has yet to integrate their designs as promised. According to a source, Tesla is currently working with JA solar to address Musk’s aesthetic concerns with the tiles.