Thread:Project:Support desk/Upload file returns "internal error"

Uploading file fails with the "internal error" key 'psbu8a87fe9iwj52kbqxy9opmdruluc.' is not in a proper format

Backtrace:


 * 1) 0 /home/u19329/hdlwiki.com/www/includes/upload/UploadBase.php(634): UploadStash->stashFile('/home/u19329/hd...', Array, NULL)
 * 2) 1 /home/u19329/hdlwiki.com/www/includes/upload/UploadBase.php(646): UploadBase->stashSessionFile(NULL)
 * 3) 2 /home/u19329/hdlwiki.com/www/includes/specials/SpecialUpload.php(367): UploadBase->stashSession
 * 4) 3 /home/u19329/hdlwiki.com/www/includes/specials/SpecialUpload.php(461): SpecialUpload->showUploadWarning(Array)
 * 5) 4 /home/u19329/hdlwiki.com/www/includes/specials/SpecialUpload.php(192): SpecialUpload->processUpload
 * 6) 5 /home/u19329/hdlwiki.com/www/includes/SpecialPage.php(579): SpecialUpload->execute(NULL)
 * 7) 6 /home/u19329/hdlwiki.com/www/includes/Wiki.php(250): SpecialPage::executePath(Object(Title))
 * 8) 7 /home/u19329/hdlwiki.com/www/includes/Wiki.php(63): MediaWiki->handleSpecialCases(Object(Title), Object(OutputPage), Object(WebRequest))
 * 9) 8 /home/u19329/hdlwiki.com/www/index.php(114): MediaWiki->performRequestForTitle(Object(Title), NULL, Object(OutputPage), Object(User), Object(WebRequest))
 * 10) 9 {main}

Does anyone know a solution for it?