Issues with "use Reduce for complete solutions"

I am getting an error:

Solve:InversefunctionsarebeingusedbySolve​,sosomesolutionsmaynotbefound;useReduceforcompletesolutioninformation

with doing differential equations using 2 vectors.
I am trying to find the equation for u(t) through solving using a system of equations, but I have been getting errors on this certain part. I was wondering if there is a way to reduce complete solutions:

Welcome to Wolfram Community! Please make sure you know the rules: https://wolfr.am/READ-1ST

The rules explain how to format your code properly. Posting code Images doesn’t help other members to copy your code. Please EDIT your post and make sure code blocks start on a new paragraph and look framed and colored like this.

int = Integrate[1/(x^3 - 1), x];
Map[Framed, int, Infinity]

You can also embed notebook or attach notebook.