Board Thread:Questions and Answers/@comment-25523075-20170104150848/@comment-28905095-20170107202012

I haven't played on a leet server, but a quick search indicates that there seems to be some issues related to which way the portal is facing. So one option could be to try placing it in all four directions.

Some of the videos also suggests building the portal in sponge or wool, and then using worldedit to replace the temporary block with the Nether Portal block.

If this doesn't help, or you're stuck somewhere you might need to post more details as to what you've tried and what is failing. Maybe post a new question (with just the one question) and a proper title to get some focus on your issue!