Hello everyone!
I get an issue with the dynmap mod. Indeed, when I try to enter the dynmap command, sponge says that an other plugin maybe use the same alias. In fact, it’s when I use the /dynmap reload command.
This issue prevent dynmap to accept any new configuration what I could do. It makes me angry a lot! 
If someone had any idea to help me, I’ll take it with pleasure! 
In case of a conflict you can use a command by running /modid:command, so for your example /Dynmap:dynmap reload may work.
But you might also want to check which mods are using that alias.
Ho! really ? god to know! 
I thinks, it’s caused by a sponge plugins. But not sure.
So I’ve tried, but Dynmap said me the same error message: “Error occurred while executing command: A plugin may not register multiple commands for the same alias (‘dynmap’)!”
wait… that means dynmap tries to register its own command again, while actually executing it already?
Go home dynmap, you’re drunk! xD
Is it dynmapforge for mc 1.8?
yes absolutely ^^
OK so I pulled Dynmap into my development environment (source code: GitHub - webbukkit/DynmapForge at 1.8.0)
(@mikeprimm fix your build.gradle! I had to add http://repo.mikeprimm.com/ manually)
It loads fine when launching (except for this message):
[Dynmap] **** DYNMAP CANNOT READ CHUNKS (UNSUPPORTED CHUNK LOADER) ****
Typing dynmap at the console works, dynmap reload doesn’t, here’s the exception stacktrace: http://pastebin.com/WTcDyiwc
It seems that dynmap is re-registering commands again when reloading which shouldn’t be allowed because the old command still exists. (forge/vanilla doesn’t seem to care and just overwrites the old command). It’s possible using SpongeAPI to unregister commands but in forge/vanilla that is not possible.
This is a dynmap issue and should be reported to them.
okay thanks for the help. But in fact, when I used previous released of Sponge, the dynmap worked fine. It appears from builds of Sponge between 945 and 1000. I can’t say exactly the version at the time, but I could search. ^^
I posted the issue with your answer on the github issue tracker of Dynmap dev. So I’m waiting for their answers!