[Responded] Can't Complete Quests - Offline Mode

I have been playing offline mode and have been having trouble completing various quests. I can speak with the NPC, and the trade window opens, I place the quest item in the trade window but nothing happens when I click the button to complete. Sometimes I can't even cancel the action (trade window stays open). I've discovered that closing out the client and restarting helps temporarily, but the bug seems to return. I've experienced this issue in Solace Bridge Outskirts, Soltown, and Ardoris. Any idea how to clear this problem up?

 

@DreadLord some encounter this behaviour in online play too
so it would help if you have steps to reproduce this behaviour on what OS etc.

 

Thanks for the response Rentier. Tonight, I logged in (I was in my house in Soltown) checked my bags to make sure I still had the quest items. I went straight to the town crier to turn in "undelivered letter". Everything worked perfectly. From there I went straight to Geoff at the refugee camp at the edge of Soltown, and the bug returned. Everything seems to be working fine until I try to click the button to complete the quest and nothing happens.

As far as my system goes, below is a summary from Speccy:

Operating System
Windows 10 Home 64-bit
CPU
Intel Core i7 4770 @ 3.40GHz
Haswell 22nm Technology
RAM
12.0GB Dual-Channel DDR3 @ 798MHz (11-11-11-28)
Motherboard
Hewlett-Packard 2AF3 (SOCKET 0)
Graphics
DELL E207WFP (1680x1050@60Hz)
2047MB NVIDIA GeForce GTX 760 (EVGA)
Storage
1863GB Seagate ST2000DM 001-1CH164 SCSI Disk Device (SATA)
55GB SPCC Solid State Disk (SSD)
Optical Drives
hp BDDVDRW CH30L SCSI CdRom Device
Audio
IDT High Definition Audio CODEC

 

I'm having a hard time reproing this. I'm in offline mode, but like what Rentier said, this has happened in online mode as well.
@DreadLord if I understand correctly, the biggest problem you are having is with the trade window and it actually completing the trade, yes?

 

Hi Lexie. Yes, I keep trying to complete quests and run into this issue. Just verified it now, the npc Geoff at the Soltown refugee camp will talk to me, I click "blade" in the npc chat interface, the trade window opens, I put the iron blade in the trade window, click "give items" and nothing happens. I click "cancel" and nothing happens. I close out the npc chat dialog and the trade window stays open.