All Good Things... (1) - S7-E25
Character mistake: When Picard jumps to the past, he meets Data for the first time in engineering. If you look at Data's uniform, he is wearing the rank insignia of a Lt, Junior Grade.
The Pegasus - S7-E12
Continuity mistake: In the opening log entry of the first episode, Picard says that "I have been informed that a highly experienced man, one Commander William Riker..." He sounds as though he has been assigned a First Officer without knowing him. However, in this episode he tells Pressman that he read Riker's file, and wanted him, based on Riker's adamant refusal to obey an order that went against his safety protocol.
Suggested correction: There's no error here. Picard likely read the files of many officers and requested the ones he preferred, and Star Fleet informed him which one he would get.