I think, better to use ore dictionary everywhere) For example, instead - , - , - . Neiplugins is very helpful.
also /MT oredict will dump all oredictionary entries into minetweaker.log and u can then just do a /MT hand on the item u have in ur hand and search for the output ( <gregtech:gt.metaitem.01:17028> ) in the minetweaker.log file and u will find the entry for the item and what oredirctionary entry its under ( <ore:plateTitanium> ).
Display Spoiler
Seems like some of this mods made a rejection for another mods, which are not installed on the server.
I have mapwriter and it writes Mod Rejection:Map-Writer 2.1.2 every time.Mapwriter is client-mod. I also have OptiFine, but no problem connecting with it.
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Update:
Problem solved. I just installed JourneyMap.
Taking my words back, problem was in my system.
Opis is a server monitoring tool that requires mobiusCore, the mapwriter refrence is because Opis is using a derivative of mapwriter as a basis for the map display ingame u get with opis. like chunkloaded, enteties etc and u also get a out of game interface so u can see whats going on more detailed on the server its installed on
clients dont need it even if server has it installed to connect.
optifine is a client mod and does nothing on a server (i believe the server wont even load because its tiggered as a CLIENT mod), same as armorhud status and alot of other mods like that.
and yes i saw u updated it saying it was on ur end just putting it there for clearification or confusion 
