In a statement to Daily Dead, Deep Silver have revealed that the patch for the PC version of Dead Island may wipe save games. A "make up" to fans that were affected by the day 1 PC issues will be offered by the company and will be announced shortly.
However a solution has been offered to help regain some quest progress:
"We tried every avenue possible in order to avoid fans having to wipe their saved games... this update may cause incompatibilities between the incorrect version of Dead Island that was released and the fixed version and cause a wipe on saved games. However, we have a solution to help regain some quest progress: When the game opens, select New Game -> Select the same character as you were using before, and then there will be an option for "Chapter Select" which will allow the player to jump to the last chapter they were playing in."
Here is a complete list of improvements in the patch:
Multiplayer and Matchmaking improvements
• Maps are now correctly synchronized when player joins during map loading
• Games now filter correctly in lobby
• After joining a coop game enemies now spawn correctly
User guidance improved. (Quest guidance, UI, shop)
Additional interface polishing
• Map tracking now works correctly after loading checkpoints
• Health and stamina bars of enemies now display correctly in coop.
• Locations of invisible NPCs are no longer shown
• More than one player can now use the same ladder simultaneously
• Focus on items in shops is not changing after operation (sell, buy)
• Additional Interface polishing
• Fixed displaying gather rings near some door
Player death behavior improved
• Respawn position now saved when playing in cooperative mode
• If player dies whilst inside vehicle, menu will now be hidden
Save game mechanics extended
• Added distinction between quest checkpoints and other saves
Minor animation fixes
• AI animation now displays correctly after fast travel or travel through portals
• Improved enemy awareness (zombies)
• Enemies reaction to fire adapted
• Enemies are now able to successfully reach player on some arenas
• Shooting enemies no longer spawn infinitely
Balancing changes in difficulty, majorly for second playthrough
• Item level will be calculated correctly when playing in second playthrough
• Kick interrupting reload now adapted, after clip wis inserted reload is treated as successful
• Health regeneration is now disabled during grab.
• More HP for all escorted NPCs
• Removed all instances of Butcher during escorts
• Purna can gain bonus rage from both "Grim Inspiration" and "Inspiring Kick"
• Only "Walker" type enemies increase the extra XP of the "Combo" skill from Xian's Survival skill tree
Pause Option added
• Added information about players requesting pause (Coop)
Looting rules improved
• Thrown items now cannot be picked up by another player for 5 minutes.
• Items from just-opened containers cannot be picked up by another player for 5 seconds.
Minor graphical glitches fixed.
• Rectified occasional graphical glitch with NPC's hands bend
• Animations now display correctly when trading
• Stomper animation now displays correctly when same target is hit by another player
Sound bugs fixed
• Volume of pickup's engine has been increased
Quest bugs removed
• All side quests in Laboratory can now be successfully completed
• Potential walkthrough blocker removed when quest "Knockin' on Heaven's Door" is completed before talking to Dominik during "On the air" quest