This method is a bit of a hack and not officially supported by Valve (i.e. If you know you're going to be using mobile data for a specific time frame, you could use this functionality as a workaround to ensure that updates are not downloaded during that specific time frame:
Under Steam > Settings > Downloads, there is now an option available that allows you to specify a specific time frame to download updates. Now there is a generic Downloads Restriction setting, too! Note that this setting will not prevent Steam from downloading updates when you're playing a non-Steam game. It is worth noting that if you're playing a game on Steam, all Steam downloads are automatically paused unless you select the download option "Allow Downloads During Gameplay" (which is available through the Steam menu > Settings > Downloads category, at the bottom), so you shouldn't experience Steam downloading files while playing Steam games.
There is a per-game setting which allows you to disable updates for individual games, which is accessible by right clicking on a game in your library, and selecting properties and choosing "Do not automatically update this game": It is not possible to prevent Steam client updates from being downloaded while the client is in 'Offline' mode.
The only way to prevent auto-updating is to run Steam in offline mode - which will prevent you from playing Steam games online. There is no generic setting within Steam that prevents game updates from automatically being downloaded. Try to validate your files and check to see if the issue persists.There is no generic setting in Steam that prevents updates.Select a location that is near to you and restart the steam client.Clicking on “Downloads” from the left pane and then changing the region. Click on “ Downloads” in the left pane and select the “ Download Region” dropdown.Open the steam client and log in to your account.Therefore, in this step, we will be changing the download region. In some cases, this glitch was fixed by changing the region in the steam settings. Sometimes a certain glitch in the steam client prevents you from validating your files. Try to validate the files now and check to see if the issue persists.Clicking on “OK” to confirm the clearing of cache. The client will display a warning message that steam will be restarted and you will need to log in again, click on “ OK” when this message is displayed.Clicking on the “Downloads” option from the left pane and selecting the “Clear Download Cache” option. Select “ Downloads” from the left pane and click on the “ Clear Download Cache” option.Clicking on the “Steam” button on the top left corner and selecting “Settings” from the drop-down. Click on “ Steam” on the top left corner and select “ Settings” from the dropdown.Open the Steam client and log in to your account.Therefore, in this step, we will be clearing the game download cache.
Steam stores cache files in order to decrease app loading time and make the experience better for the users however, this cache can get corrupted over time and cause issues with the validation process.
This can help to reinitialize the application and might remove any bugs or glitches that arise due to the client not loading properly. When you encounter the error the most basic troubleshooting step is to try to restart the Steam client after completely closing it through the task manager. Make sure to implement these solutions in the specific order in which they are provided to avoid any conflicts. Now that you have a basic understanding of the nature of the problem we will move on towards the solutions.
Bug/Glitches: It is possible that the steam client encountered a bug or a glitch and cannot continue the validation process.