EDIT:
1)Tried starting the launcher again and now it suddenly works… oh well.
2) The Yes and No button in the error message you can see in the printscreen seems to be doing the opposite: Pressing No doesn’t close the launcher but it tries again where as pressing Yes just straight up closes it.
ORIGINAL POST
I just bought the game and are having problems getting the launcher to work. I downloaded the installation file and then tried to start the launcher. No matter what I try I always get an error saying:
Error
An unknown error has occured. Would you like to try again?
Yes No
I’ve tried starting the launcher with administrativ privileges but to no avail. I’ve tried to uninstall the game → reboot → clear out remaining files/folders that the uninstallation process didn’t delete → reboot → install but the error remains.
Also, according to your guide for troubleshooting there should be a folder in AppData but after all these tries I’ve never seen it being created.
I’ve also tried to install it in different folders other than the default.
Since I am a new user it seems I can’t upload the .txt file. I hope that it’s fine that I’m putting the raw data into this post instead. I’ll also add a space in one of the links below since there seems to be a limitation on #number of links in the post since I can’t upload the file 
########## tis apr 30 14:17:02 2019 - Log start
[INFO] tis apr 30 14:17:02 2019 - Successful lock on “.lock”
[INFO] tis apr 30 14:17:02 2019 - Updating the patcher
[INFO] tis apr 30 14:17:02 2019 - Getting the latest app version for app “7bc4f49fcabe004069788293d85d5e56”
[INFO] tis apr 30 14:17:02 2019 - Executing GET “1/apps/7bc4f49fcabe004069788293d85d5e56/versions/latest/id”
[INFO] tis apr 30 14:17:02 2019 - Downloading from “https ://api2.patchkit.net/1/apps/7bc4f49fcabe004069788293d85d5e56/versions/latest/id” with timeout 10000
[INFO] tis apr 30 14:17:02 2019 - Checking whether patcher is installed.
[INFO] tis apr 30 14:17:02 2019 - Installation file doesn’t exists - “D:/Program Files (x86)/Last Epoch/patcher/install_info”
[INFO] tis apr 30 14:17:02 2019 - Installation not found.
[INFO] tis apr 30 14:17:02 2019 - Getting the content summary for app “7bc4f49fcabe004069788293d85d5e56” version 15
[INFO] tis apr 30 14:17:02 2019 - Executing GET “1/apps/7bc4f49fcabe004069788293d85d5e56/versions/15/content_summary”
[INFO] tis apr 30 14:17:02 2019 - Downloading from “https://api2.patchkit.net/1/apps/7bc4f49fcabe004069788293d85d5e56/versions/15/content_summary” with timeout 10000
[INFO] tis apr 30 14:17:03 2019 - Getting the content urls for app “7bc4f49fcabe004069788293d85d5e56” version 15
[INFO] tis apr 30 14:17:03 2019 - Executing GET “1/apps/7bc4f49fcabe004069788293d85d5e56/versions/15/content_urls”
[INFO] tis apr 30 14:17:03 2019 - Downloading from “https://api2.patchkit.net/1/apps/7bc4f49fcabe004069788293d85d5e56/versions/15/content_urls” with timeout 10000
[WARNING] tis apr 30 14:17:04 2019 - Chunked download did not succeed
[INFO] tis apr 30 14:17:04 2019 - Unlocking the lock file.
[CRITICAL] tis apr 30 14:17:04 2019 - UpdateFailed: Failed to update
[INFO] tis apr 30 14:17:04 2019 - Asking the user to either retry or go into offline mode
[DEBUG] tis apr 30 14:17:04 2019 - Initializing path.
[DEBUG] tis apr 30 14:17:04 2019 - Path set to “D:/Program Files (x86)/Last Epoch”
[INFO] tis apr 30 14:17:04 2019 - Checking whether patcher is installed.
[INFO] tis apr 30 14:17:04 2019 - Installation file doesn’t exists - “D:/Program Files (x86)/Last Epoch/patcher/install_info”
[INFO] tis apr 30 14:17:04 2019 - Asking the user if Launcher should retry.
[INFO] tis apr 30 14:17:04 2019 - Asking if launcher should retry
[INFO] tis apr 30 14:17:06 2019 - Answer was true
[INFO] tis apr 30 14:17:06 2019 - The user decided to retry
[INFO] tis apr 30 14:17:06 2019 - Close window request.
[INFO] tis apr 30 14:17:06 2019 - Allowing the window to be closed.
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