MuzTank

Ah I found the answer, it's all because of loading screen... I don't know what is the difference between this "broken" loading screen with others, except its file size is much2 bigger...

The "broken" loading screen:

Spoiler

I will record it later to show the error...
This case is not happening if Im not using the Translation+CustomProntera GRF. (Only kRO's data.grf and rdata.grf), that's why I suspect the LUA file from the Translation Project.
I dont think so for item error, because I was alone and not using any items/headgear, also no items in inventory

@Dastgir @zackdreaver

OS: Windows 10 64-bit
RAM 12GB

Intel Core i5 @2.4GHz

In the client GRF, only Translation Project + New Prontera Theme

In the server, nothing modification / custom items

Diff used

2 Chat Flood Allow5 Enable Proxy Support (Experimental)6 Force Send Client Hash Packet (Experimental)8 Custom Window Title13 Disable Ragexe Filename Check (Recommended)15 Disable HShield (Recommended)18 Skip Service Selection Screen19 Enable Title Bar Menu20 Extend Chat Box21 Extend Chat Room Box22 Extend PM Box24 Fix Camera Angles (Recommended)28 Increase Headgear ViewID32 Increase Zoom Out Max33 Always Call SelectKoreaClientInfo() (Recommended)34 Enable /showname (Recommended)36 Read msgstringtable.txt (Recommended)37 Read questid2display.txt (Recommended)38 Remove Gravity Ads (Recommended)39 Remove Gravity Logo (Recommended)40 Restore Login Window (Recommended)41 Disable Nagle Algorithm (Recommended)43 Always Use Email for Char Deletion44 Translate Client (Recommended)48 Use Plain Text Descriptions (Recommended)49 Enable Multiple GRFs (Recommended)50 Skip License Screen52 Use Custom Font61 Disable Packet Encryption64 @ Bug Fix (Recommended)65 Load Custom lua file instead of iteminfo.lub68 Enable 64k Hairstyle69 Extend Npc Dialog Box73 Remove Hourly Announce (Recommended)204 Increase Attack Display75 Enable Flag Emoticons211 Use Custom DLL213 Disable Help Message on Login (Recommended)84 Remove Serial Display (Recommended)88 Allow space in guild name90 Enable DNS Support (Recommended)97 Cancel to Login Window (Recommended)