critical

The aforementioned limited visibility of the arbiter presents a critical problem for real-time processing such as the real-time processing of video and audio decoders.
US Pat. 6701397

A critical problem in the implementation of using avatars as proxies is the latency involved in transmitting information between the avatar and the user who is controlling the avatar.
US Pat. 5884029

One critical problem has to be overcome involving the formation of a complete silicon dioxide region 22 to fully dielectrically isolate the monocrystalline regions 30.
US Pat. 4104090

A less critical problem exists in the case of the logical sector containing leaf node C (506), in that this sector still is shown as already allocated in the media allocation map on the storage volume.
US Pat. 4750106

＊「深刻な」SYN
・acute 〈事態が〉緊急の注意を必要とする: The shortage of water became acute. 水不足が深刻になった.
・critical 〈事態や時期が〉岐路に立って重大なまたは深刻な: The patient has passed the critical stage. その患者は深刻な事態を脱した.
・serious 〈事態が〉重大な, 〈様子が〉真剣な, など一般的な意味で用いられる: She had a serious expression on her face. 彼女は深刻な顔をしていた.
（研究社　新英和大辞典より引用）