Here is a little background before I begin into the issues that I have occurred in this quest:
I’ve completed the main storyline, in which I traded Markarth to the Stormcloaks in exchange for Riften to the Imperials. Then I began the Civil War storyline for the Imperials.
On to my issues:
The first couple quests in this storyline went well. But when I began the Reunification of Skyrim, some issues began to occur. For instance, there was a lack of battle music while I was taking part in the quest, The Battle for Fort Dunstad. After completion of that quest, I reported to General Tullius where he then sent me to regain the Winterhold Hold. The game skipped two quests in the middle, Compelling Tribute and The Battle for Fort Greenwall. I was a bit upset about this, because I already had Riften exchanged and had expected a Markarth based quest in its place. Anyways, I went to Legate Rikke to receive my quest details. She had no speech prompt to begin the quest Rescue from Fort Kastav.
I have tried waiting and reapproaching her. I have tried attacking her and approaching her. I have also tried saving and reloading then approaching her. There is still no speech prompt. I’m disappointed at this point. I was curious to know if anyone on this forum or from Bethesda has encountered this issue before. I also decided to post this to make Bethesda aware of another issue. Any ideas?

I'm sorry, were you expecting a working game? Bethesda don't do those.

There are more issues than you realize. During my last Playthrough, I had two bugs where the map did not recognize that I had taken some of the forts, and that people still believe the civil war continued after the death of the respective General. Whiterun still had broken buildings as well. I don't know whether thats intentional or is just a bug, but it aggravated me.

Oh, I realize there are a ton of issues with this game. But this is the only issue that I have had that directly affected any of my quest-lines. I do feel your pain though, as the buildings in my game still haven't been fixed (I'm thinking that it may be intentional) and the NPCs are basically unaware. I just thought that I'd bring another issue to Bethesda's forefront, along with the still growing stack of problems.
Mechfish, I'm disappointed that you feel that way about TES: Skyrim but there is no need to be short and cynical. Frankly, I still believe this game is worthwhile.