Question: An error message is appearing in GTAV PC saying “ERR_GEN_ZLIB_2 Failed zlib call. Please reboot or reinstall the game.” Do I really need to reinstall or can I just reboot?

Answer: Rebooting will probably not fix this error message, which suggests that installation data is corrupt.

If using the disc version, you can attempt to repair GTAV from the discs. If on Steam, you can try to verify game cache to fix the installation.

If the error still appears after trying those steps, or if you are using a digital version downloaded from Social Club, go to Add/Remove programs in your Windows Control Panel and uninstall GTAV. Then reinstall the game, either from the discs or by downloading directly from the Social Club GTAV Activation Page.