Received an error after importing a free asset map

I'm not the best at using Unity, and I'm learning it as a student first year. I'm kind of messing around and testing things here and there. I decided to try something new, getting a map from the asset store and importing it into Unity to try some new things out. I got the Flooded Grounds by Sandro T, it's downloaded and imported into my project, and straight away I got an error:
Assets\Flooded_Grounds\PostProcessing\Editor\PropertyDrawers\MinDrawer.cs(6,34): error CS0104: 'MinAttribute' is an ambiguous reference between 'UnityEngine.PostProcessing.MinAttribute' and 'UnityEngine.MinAttribute'

What do I do? How can I fix this? In case if anyone is wondering, I'm currently using Unity 20201.3.8f1

 

In the file listed, you will find a line that starts

[Min(...)]

.
Replace it with

[UnityEngine.Min(...)]

, leaving whatever the ... part is alone.
See if it makes any errors. Probably not. If it does, try

[UnityEngine.PostProcessing.Min(...)]

instead.

You're not the first to have this exact error, and the Unity guys should fix it, and the asset author should also fix it since Unity hasn't. Contacting an asset's author (Sandro T) is the first thing you should try in cases like this.

But this has nothing to do with "Game Design", this forum area. It's more of a Scripting question.