Oh trust me I can exit Steam, run the repair utility, run sfc /scannow from Windows cmd prompt, restart the computer, verify the CSGO game cache when I get back on, all before the reconnect timer is up. But it just gives me the error again and never lets me reconnect until another 10 minutes or so has passed. I seem to get it every couple of games I play.
The in-game error popup makes you hit okay and then minimizes the game to open this page
https://support.steampowered.com/kb_article.php?ref=2117-ilzv-2837 but nothing on there really helps. The only application I have from their list of common causes is CCleaner but I only run that on-demand and have its automatic monitoring/cleaning stuff turned off.
Other related support pages suggest firewall issues with common Internet Security/Antivirus applications, but I've still gotten the error even with my software firewall disabled, and besides, CSGO and Steam were correctly automatically excluded in the software anyway so they should be able to make all the connections they need regardless.