How to remove any data "http_proxy" module added or changed? I have a serious problem with a broken XML-Feed, that occurred after I installed http_proxy module. I have uninstalled the module, cleared the cache several times and even truncated the cache tables of the database manually. (I have to admit i didn't made a database backup before the installation). The XML feed is flawless, actually it didn't change at all.

I have following error messages:

in the drupal log:


  Notice: Undefined offset: 1 in http_request_get() (Zeile 239 von
  /example.com/sites/all/modules/feeds/libraries/http_request.inc).


The error message above is 2 times in the log with the same timestamp.
Then more recent:


  Warning: simplexml_import_dom(): Invalid Nodetype to import in
  FeedsExXpathDomXpath->__construct() (Zeile 393 von
  /example.com/sites/all/modules/feeds_ex/src/FeedsExXml.inc).


followed by
from the feeds module log:


  Start tag expected, '&lt;' not found on line 1. Error code: 4


So i guess this comes from the http_proxy module. How can i remove any trace of it? Does someone have another idea where to look?

Thanks!
Uninstalling the HTTP proxy module appears to not uninstall its configuration. So the proxy configuration is likely still in place in your case. I assume that the reason the HTTP proxy module does not remove the configuration is that it doesn't explicitly "owns" the configuration: it exposes hidden settings from Drupal core.

There is an issue about this reported in the http_proxy issue queue: https://www.drupal.org/node/2592461