What is the law if one accidentally skipped the middle of the blessing of Yotzer Or?
If one began the blessing of Yotzer Or properly, and after saying the first few sentences accidentally skipped the remainder of the paragraphs and recited straight away it’s concluding blessing of Yotzer Hameoros, nevertheless fulfills his obligation and is not required to repeat the blessing. This applies even though he did not say the Kedusha within the middle blessing.
Shabbos: The above law applies likewise to the Shabbos Davening, that if one accidentally skipped the entire middle part of the blessing, including the additional Shabbos paragraphs of Keil Adon and Lakeil Asher Shavas, he nevertheless fulfills his obligation and is not to repeat the blessing. He is likewise not to say the additional part of Lakeil Asher Shavas upon remembering, although it is proper to recite it after the Shacharis prayer.
 See Admur 59:1 [that so long as one said the opening and concluding blessing properly he fulfills his obligation, and thus even if he accidentally began saying the Maaariv blessing of Asher Bidvaro Maariv Araviim immediately after saying the words Yotzer Or Uvoro Choshech, he nevertheless fulfills his obligation if he concluded properly with the blessing of Yotzer Hameoros]; Admur 66:12 [regarding the after blessing of Emes Veyatziv and that this rule applies by all long blessings the one who did not say the middle of the vesting properly nonetheless fulfills his obligation]; Michaber 59:2; Taz 59:1 in explanation of Michaber ibid; See also Admur 68:1; 114:8; 167:13; 187:4; 188:8
 The reason: As since the opening blessing and its conclusion were said properly as established by the sages, therefore he fulfills his obligation Bedieved, even though that in the middle of a blessing he changed from the wording that the sages set. [Admur 59:1; 66:12]
 Admur 281:2
[4 Admur ibid in parentheses;
[5 Admur ibid; M”A 281:3 in opinion of Rama and Or Zarua