Death to the leaders glitch

[Thornapple]

hey guys (sorry if reposted)

for the last week or so every time i log in to my game it tells me i have a completed quest. however i can click accept or whatever and it just keeps giving me 50xp, that does not count. The quest is not truly valid and appears every time i refresh or reopen the game, it often also then freezes and i have to refresh again.
im level 32 and only have 3 or so bandit camps left. so i do not see the relevance of this early quest re-appearing. any help is welcome:)
ive attached 2 screenshots of what it does :)52035204
thanks

[Tierarzt]

First thing you can try, is increase the flash cache to maximum. It doesn't cure every problem but it does cure a lot of them.

[Fexno]

It is indeed already discussed in several other threads. The longest (and probably oldest thread can be found here)