Hi everyone,
Anyone has had that issue? I've had it since last monday. I tried uninstalling and installing the game (it was getting super laggy since the new gen update) and I can't install the game anymore. I tried erasing the game files on GOG, and redownload them. Nothing. I looked at my firewalls exception, no problem there. I have enough space on my HD. I don't know what else to do. It's really frutrating. I've contacted the support and nothing came of it.

Hello,

1. Click the cog wheel in the top left corner and choose Settings, then Installing, updating.
2. In File Explorer, create new folders in the root of the drive for each of these: Game installation folder, Temporary game update folder, Other downloads folder. Then select those folders in the Settings window. Restart GOG Galaxy afterwards.
3. Double-check your security software settings. Anything that scans those folders or files as they're being created could be a problem, and the game goes for anything that filters Internet connections. The support article recommends whitelisting the following executables:
• C:\Program Files (x86)\GOG GALAXY\GalaxyClient.exe
• C:\Program Files (x86)\GOG GALAXY\GalaxyClientService.exe
• C:\ProgramData\GOG.com\Galaxy\redists\GalaxyCommunication.exe
4. Average support response time is 5 weeks. If you haven't already done so, exit GOG Galaxy, then zip up the following folder and attach it to your support ticket:
• C:\ProgramData\GOG.com\Galaxy\logs
5. E4 is too short of a keyword to search the forum, but you can use a web search engine instead. See if any of the following threads help:
• https://www.gog.com/forum/general_beta_gog_galaxy_2.0/installation_failed_e4/post12
• https://www.gog.com/forum/deus_ex_mankind_divided/installation_error_installation_failed_e4_with_gog_version/post6
• https://www.gog.com/forum/general_beta_gog_galaxy_2.0/problemmacosinstallation_failede4/post4