Here is an example curl request you can test:
curl 'http://your-server.tld/test.php?M=user_setup&moduleToken=1b9047ae59a852bd3158019ed38d612c342bda67' -H 'Cookie: be_lastLoginProvider=1433416747; PHPSESSID=pamp04afm2d46m6k57agm309k1; be_typo_user=559ddca68304a1a26ee948870461bf19; Typo3InstallTool=ni98ca552e62ajkeergvo11q16' -H 'Origin: http://t6-001.ternum-dev.de' -H 'Accept-Encoding: gzip, deflate' -H 'Accept-Language: de-DE,de;q=0.8,en-US;q=0.6,en;q=0.4' -H 'Upgrade-Insecure-Requests: 1' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.86 Safari/537.36' -H 'Content-Type: multipart/form-data; boundary=----WebKitFormBoundary6OOg3F3POrOky32q' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8' -H 'Cache-Control: max-age=0' -H 'Referer: http://t6-001.ternum-dev.de/typo3/index.php?M=user_setup&moduleToken=1b9047ae59a852bd3158019ed38d612c342bda67' -H 'Connection: keep-alive' --data-binary $'------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[save]"\r\n\r\n1\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[be_users][realName]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[be_users][email]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[be_users][avatar]"\r\n\r\n0\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[lang]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[be_users][passwordCurrent]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[be_users][password]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[be_users][password2]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[startModule]"\r\n\r\nhelp_AboutmodulesAboutmodules\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[thumbnailsByDefault]"\r\n\r\non\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[titleLen]"\r\n\r\n50\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[edit_RTE]"\r\n\r\non\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[edit_docModuleUpload]"\r\n\r\non\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[resizeTextareas_MaxHeight]"\r\n\r\n500\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[copyLevels]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[rteWidth]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[rteHeight]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[rteMaxHeight]"\r\n\r\n\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[rteCleanPasteBehaviour]"\r\n\r\nplainText\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="simUser"\r\n\r\n0\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="formToken"\r\n\r\n1adcee0bc7fcb29b291a9037887c6fb16e027174\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[save]"\r\n\r\n1\r\n------WebKitFormBoundary6OOg3F3POrOky32q\r\nContent-Disposition: form-data; name="data[setValuesToDefault]"\r\n\r\n0\r\n------WebKitFormBoundary6OOg3F3POrOky32q--\r\n' --compressed
Please note to adapt the path to
http://your-server.tld/test.php
The contents of this file just is:
<?php
var_dump($_POST);
The server I tested for Nico, discarded parts of the $_POST vars, which is the severe error condition I mentioned above.
I have no idea what can cause such errors, maybe a devops or ops person can help out here, but in this case we cannot do anything in TYPO3 to fix such broken setup.