I had previously installed um-olsr in my ns2 but it stopped working one day .so I again tried to patch but I am getting a huge number of errors. I have followed all the instructions at masimum website but couldn’t succeed Here is the recent issue umair@umair-VirtualBox:~/ns-allinone-2.34/ns-2.34$ patch -p1 < olsr/um-olsr-2.34_v0.8.8.patch patching file Makefile.in Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 276. 1 out of 1 hunk FAILED -- saving rejects to file Makefile.in.rej patching file common/packet.h Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 182. Hunk #2 succeeded at 395 with fuzz 2 (offset 12 lines). 1 out of 2 hunks FAILED -- saving rejects to file common/packet.h.rej patching file queue/priqueue.cc Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 92. 1 out of 1 hunk FAILED -- saving rejects to file queue/priqueue.cc.rej patching file tcl/lib/ns-agent.tcl Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 197. 1 out of 1 hunk FAILED -- saving rejects to file tcl/lib/ns-agent.tcl.rej patching file tcl/lib/ns-default.tcl Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 1363. 1 out of 1 hunk FAILED -- saving rejects to file tcl/lib/ns-default.tcl.rej patching file tcl/lib/ns-lib.tcl Hunk #1 succeeded at 642 with fuzz 2 (offset 9 lines). Hunk #2 succeeded at 897 (offset 33 lines). patching file tcl/lib/ns-packet.tcl Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 169. 1 out of 1 hunk FAILED -- saving rejects to file tcl/lib/ns-packet.tcl.rej patching file trace/cmu-trace.cc Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 53. Hunk #2 succeeded at 1213 (offset 151 lines). Hunk #3 succeeded at 1563 with fuzz 2 (offset 157 lines). 1 out of 3 hunks FAILED -- saving rejects to file trace/cmu-trace.cc.rej patching file trace/cmu-trace.h Reversed (or previously applied) patch detected! Assume -R? [n] Apply anyway? [n] y Hunk #1 FAILED at 160. 1 out of 1 hunk FAILED -- saving rejects to file trace/cmu-trace.h.rej umair@umair-VirtualBox:~/ns-allinone-2.34/ns-2.34$ I want to install it in clean way from starting but it says previously patched so what should I do ?How can I reinstall the patch ,remove all rej files without disturbing my ns2 configurations .?