Sharecloudy refuses the connection, the browser displays an error, but the rest of the web responds normally. This discrepancy points to a localized blockage between the client machine and the target server, not a global network outage. Identifying the responsible layer can save considerable time on diagnosis.
DDoS Mitigation and IP Blocking by the Host: The Path Not Shown by the Browser
Hosts and cloud providers have generalized automated DDoS mitigation mechanisms that block certain IP addresses deemed suspicious. The result for the user: a connection refusal targeted at a single service, while everything else works.
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This type of blockage does not always generate an explicit message. The browser may return an ERR_CONNECTION_REFUSED or a timeout without specifying that the request was intercepted upstream of the application server. We regularly observe this behavior on shared IPs (corporate NAT, public hotspots) where another user from the same pool has triggered a security rule.
To verify this hypothesis, simply test access from a mobile network or a VPN. If Sharecloudy responds normally on another network path, the blockage is indeed related to the outgoing IP address. The resolution then involves contacting the host or changing the public IP (restarting the router, switching between 4G/5G). When encountering a connection issue on Sharecloudy with this profile, the cause rarely lies on the client side.
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Intermediate Filtering in the Workplace: Proxy and HTTPS Middlebox
In a professional environment, the majority of HTTPS traffic passes through a filtering middlebox (Zscaler proxy, Forcepoint, Palo Alto) that inspects outgoing connections. These devices maintain categorization lists of domains, and a recent or poorly categorized cloud service may fall under a default blocking rule.
The symptom is identical: the internet works, standard sites respond, but Sharecloudy remains inaccessible. The difference from a host blockage is that testing from the same network while bypassing the proxy (if policy allows) restores access.
Check Proxy Configuration on the Machine
On Windows, we recommend checking two locations:
- The system settings (Settings, Network & Internet, Proxy) to detect a manually configured proxy or an active PAC script
- The browser settings themselves, as Chrome and Firefox may have their own proxy configuration independent of the system
- The HTTP_PROXY and HTTPS_PROXY environment variables if the machine runs command-line tools that access the service
A leftover VPN configuration can also cause this behavior. Some VPN clients inject static routes or proxy rules that persist after disconnection. Properly uninstalling the VPN client (not just disconnecting it) eliminates this possibility.
DNS Resolution Filtered by the ISP: Selective Blocking of Cloud Domains
For several years, several French and European ISPs have applied selective DNS blocking related to policies against hosting illegal content. These filters do not cut off the internet globally; they simply make certain domains unresolved via the ISP’s default DNS servers.
The diagnosis is quick. Open a terminal and execute a manual DNS query to a third-party resolver:
nslookup sharecloudy.com 1.1.1.1 (Cloudflare) or nslookup sharecloudy.com 8.8.8.8 (Google). If the domain resolves correctly with a third-party DNS but fails with the ISP’s DNS, the blockage is confirmed.
Change DNS Resolver on the Machine
The modification is made in the settings of the active network adapter. On Windows: Settings, Network & Internet, select the active connection, then change the DNS server assignment to manual. Entering a public resolver as an alternative to the operator’s DNS usually suffices to restore access.
On a corporate network, this manipulation may be locked by group policy (GPO). In this case, only the network administrator can intervene at the level of the internal DNS server or firewall.
Browser Cache and TLS State: When the Problem Persists After Network Correction
The browser caches connection information that can perpetuate a blockage even after the initial problem has been resolved. Two mechanisms are involved.
The first is the browser DNS cache. Chrome maintains its own cache of DNS resolutions, separate from that of the system. To clear it: chrome://net-internals/#dns then “Clear host cache”. Firefox has a similar mechanism via about:networking#dns.
The second concerns HSTS (HTTP Strict Transport Security) states. If Sharecloudy sent an HSTS header during a previous connection and the TLS certificate has issues, the browser will refuse any unsecured connection without even displaying a bypassable error page. Removing the HSTS entry from the browser resolves the situation.
- Chrome: chrome://net-internals/#hsts, search for the domain and remove it from the list
- Firefox: remove the entry via the SiteSecurityServiceState.txt file in the user profile
- Edge: the mechanism is identical to Chrome (same Chromium base)
Extensions and Antivirus with Web Filtering
Security extensions (HTTPS Everywhere in its older versions, some ad blockers) and web filtering modules built into antivirus software intercept HTTPS connections. We recommend testing in private browsing mode with no extensions enabled to isolate this variable. If access works in private mode, disabling extensions one by one identifies the culprit.
The diagnosis of a connection refusal targeted at a single cloud service follows a logic of elimination by layers: host, intermediate network, DNS, then browser. Testing from an alternative network remains the most discriminating action to quickly direct the investigation to the correct layer.