You are giving an incomplete picture here, so I will state some assumptions about what you are doing/using.
I assume you are running a design rules check (DRC) which is producing this error message. You didn't state what process and PDK you are using, nor did you state the type of capacitor. For some caps like MIMs, there may be rules associated with nearby metals and rules for the metal connections to either plate of the cap.
You should look at M1 and how it overlaps LSM, which might stand for the lower side metal or bottom plate of a MIM cap. Make sure it overlaps at least 10 um. Just a guess though, since so few details are provided.