thanks for the answer. the command merge points is a powerful command which i have not known. thanks. but i'm still not able to fix the following warning:
2. UG, F4 & F413 are too close. Check at (179,622,296,385,3,15)
2. UG, F413 & F414 are too close. Check at (161,803,262,212,3,15)
Check...