It can be triggered if there is write protection enabled on the drive, due to corrupted game files, because of corrupted download cache, bad sector and other disk errors, etc.

If you cannot Update or Install Steam games & you see An error occurred while installing or updating game - App running, Invalid platform, Unknown error, etc, see ...

Steam is an online platform that is widely used among gamers in the gaming community. With Steam app, you can download and install games on your computer. Although downloading a game on Steam ...

The Download Try to sync your Steam Cloud again, as a quick internet fix could solve the problem. Ensure your computer is set to sync with Steam Cloud to avoid losing your game progress.

Right click on the selection and click Delete from the drop down menu. Double click on Steam executable to download steam again. Check if Steam On Allocating Disk Space stuck issue still occurs.