I walk into a nether portal on my mcprohosting server and it loads me into the void and I die

Put the summary of the bug you're having here

What I expected to happen was...:
I should appear in the nether and have fun

What actually happened was...:
I didn't appear in the nether but the void which was not fun

Steps to Reproduce:
1. Build a 5x5 nether portal (5x5 obisidian and 3x3 portal blocks)
2. Walk into the nether portal
3. Wait and you shall die