THIS STEP SHOULD BE PERFORMED BY THE ONE WITH THE YELLOW TRIANGLE!
Step1: Go to the Hamachi Systems Tab.
Step2: Click Preferences under the Systems Tab.
Step3: Click the Setting Tab.
Step4: Make sure to disable Encryption and Compression.
Step5: Restart Hamachi.
This should remove the Yellow Tringle and enable you to be pinged by others.
PS: If it doesn't work, try right clicking some of the members in your network and click details. on the Settings Tab, make sure that all of you have the same settings. then restart Hamachi.
I hope this helps.
-3rdYear IT student major in ANIMATION. XD hahaha