Getting this error in console when trying to load MyMiniCopter  

Error while compiling: MyMiniCopter.cs(646,67): error CS0029: Cannot implicitly convert type `System.Collections.Generic.List<BaseVehicle.MountPointInfo>' to `BaseVehicle.MountPointInfo[]'

You are using an old version of the plugin, but please see existing threads regarding current issues.

On the umod website the plugin has not been updated in 2 months and was working fine yesterday

The plugin has not been named "MyMiniCopter" in over 2 months. There are existing threads with the current issues, please see those.

Can u please give me a link to the new mod as i cant find it 

You posted under the section for it: https://umod.org/plugins/spawn-mini