Assassination Rogue is recommending item level gear a few hundred ilvl below the maximum for Dragonflight (ex: Shadowlands legendaries and Legion Artifact Weapons or Trinkets). In todays sim, the website completely broke and I was prompted to make a forum post with the snapshot ID.
We’ll take a look at this error and post a fix for it in the update we’re doing mon or tues for the 10.1 patch.
As for the weapons, that usually only happens when you don’t have enough appropriate weapons in your inventory (reasonable ilvl agility weapons, daggers for assassination, etc.).
I’ll fix the bug so it doesn’t error out. You can avoid it for now by not trying to optimize a build for mythic+ that doesn’t have Seal Fate. I didn’t even test for that, hah.
We will be doing an update later today before the servers come back up. If you are still having this problem after the update, please let us know and post a snapshot. I can’t load this snapshot anymore on my development version because we have switched over to the 10.1 talent trees.