Recently–either here or in the Facebook group–someone mentioned bars with missing beats. I commented that it had happened to me. Today, it happened and I captured the example. This piece is in 12/8 but there is one bar of six.
Note for former Finale users: Now that I am used to it, I love the way Dorico allows any type of tuplets: 2 on 3, 3 on 2, 7 on a beat, etc. You have to have the math clear in your head, but Dorico will do whatever you need.
Unless you have Insert mode turned on, adding a time signature will only rebar the music as far as the next time signature.
For these purposes, non-default barlines (such as double barlines) are classed as time signatures.
It’s difficult to know the order in which you placed the various things on the page, but if there was already a double barline after the dotted half/minim now in bar 117, adding anywhere to the left of that would only rebar the music up to the end of that dotted half/minim.
Turning on Insert mode before adding a time signature will allow Dorico to extend the final bar before the next time signature or non-default barline. Alternatively, if the addition of a time signature has resulted in a bar that is too short, you can place the caret anywhere in that bar and type Shift-B 3q Enter (where the number specifies the number of beats and the letter specifies the length of beat = w for whole, h for half, q for quarter, e for eighth etc.).