# [Solved] Overleaf Compile the Paper Error: LaText Error:Environment aligned undefined.

Problem Description:

Use online overflow to compile the paper, and the errors in the formula part are as follows.

Problem solving:

This “environment XXX undefined” problem is mostly caused by the fact that packages are not introduced. The solution is to introduce corresponding packages

The solution to this error is to import the amspath package, that is, add this line where the package was imported first.

``\usepackage{amsmath}``