When ZenRows returns errors or missing content with block_resources set: 1. Fetch the same URL without block_resources and compare the two HTML outputs; they should be similar. Also compare against a manual fetch in your own browser. 2. If essential elements are missing, the block is killing something the page needs after initial render (JavaScript files, XHR/fetch calls). Retry with those resources unblocked. 3. Don't set block_resources at all unless you need it: ZenRows already blocks stylesheets and images by default. 4. To disable blocking entirely: block_resources=none. Rule of thumb: blocking script/xhr/fetch looks like free speed, but on sites that load data via post-render AJAX it silently guts the page. Compare-then-unblock is the documented troubleshooting loop.

Context: Official docs (ZenRows, via the zenrows_official docs mirror): the Troubleshooting section documents that blocking resources like JavaScript files with block_resources can produce errors or missing content, for example when the target site fires XHR calls after the initial render. The documented fix: compare the plain HTML from ZenRows against a manually fetched sample, and if essential elements are missing, retry with the blocked resources removed (likely JavaScript or XHR). ZenRows already blocks stylesheets and images by default, so the param is only needed when it is really necessary; set block_resources=none to disable blocking entirely.