This could be problem with Okular.

Does the problem only occur with one specific LaTeX/PDF file? If so, would it be possible for you to attach that file here?

It occurs with any tex file even a minimal one.

Hello,

I have EXACTLY the same bug ! When I open Kile by "./run.sh" I get this message error : "Could not open /home/inf0phile/kile-livepreview/.kde/share/apps/kile/livepreview/preview-ONaCzE//essai.pdf" with a minimal tex file "essai.tex" :

\documentclass[12pt]{article}
\begin{document}
\section*{Notes for My Paper}
Example
\end{document}

But the "essai.pdf" is correctly created and I can visualize it manually with okular ! And once this message error appeared, if I click somewhere Kile is crashing ! I have the same backtrace :

Application: Kile (kile), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f60c152c780 (LWP 21865))]

Thread 9 (Thread 0x7f60ac4d5700 (LWP 21866)):
#0  0x00007f60bcfa8303 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f60b8c25036 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b8c2549a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60ac4da98b in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#4  0x00007f60b8c469e5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f60bab42e9a in start_thread (arg=0x7f60ac4d5700) at pthread_create.c:308
#6  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 8 (Thread 0x7f60abcd4700 (LWP 21867)):
#0  0x00007f60bcfa8303 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f60b8c25036 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b8c2549a in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60b08eb406 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007f60b8c469e5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f60bab42e9a in start_thread (arg=0x7f60abcd4700) at pthread_create.c:308
#6  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 7 (Thread 0x7f60aa030700 (LWP 21868)):
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:215
#1  0x00007f60b8c60925 in g_cond_wait_until () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b8bfb1c1 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60b8bfb7da in g_async_queue_timeout_pop () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f60b8c47164 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f60b8c469e5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007f60bab42e9a in start_thread (arg=0x7f60aa030700) at pthread_create.c:308
#7  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#8  0x0000000000000000 in ?? ()

Thread 6 (Thread 0x7f609800e700 (LWP 21869)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f60be75c4db in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#2  0x00000000005d3493 in KileParser::ParserThread::run (this=0x1a12130) at /home/inf0phile/kile-livepreview/src/kile/src/parser/parserthread.cpp:169
#3  0x00007f60be75bfcb in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007f60bab42e9a in start_thread (arg=0x7f609800e700) at pthread_create.c:308
#5  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#6  0x0000000000000000 in ?? ()

Thread 5 (Thread 0x7f609780d700 (LWP 21870)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f60be75c4db in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#2  0x00000000005d3493 in KileParser::ParserThread::run (this=0x1a23550) at /home/inf0phile/kile-livepreview/src/kile/src/parser/parserthread.cpp:169
#3  0x00007f60be75bfcb in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007f60bab42e9a in start_thread (arg=0x7f609780d700) at pthread_create.c:308
#5  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#6  0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7f609566c700 (LWP 21871)):
#0  0x00007f60bcfa8303 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007f60b8c25036 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f60b8c25164 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f60be88a3bf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#4  0x00007f60be859c82 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#5  0x00007f60be859ed7 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#6  0x00007f60be758fa7 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#7  0x00007f60be8399ff in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#8  0x00007f60be75bfcb in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#9  0x00007f60bab42e9a in start_thread (arg=0x7f609566c700) at pthread_create.c:308
#10 0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7f6087fff700 (LWP 21873)):
#0  0x00007f60bcfad023 in select () at ../sysdeps/unix/syscall-template.S:82
#1  0x00007f60be83906f in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#2  0x00007f60be75bfcb in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#3  0x00007f60bab42e9a in start_thread (arg=0x7f6087fff700) at pthread_create.c:308
#4  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f608741f700 (LWP 21936)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
#1  0x00007f60bff73222 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#2  0x00007f60bff73259 in ?? () from /usr/lib/x86_64-linux-gnu/libQtScript.so.4
#3  0x00007f60bab42e9a in start_thread (arg=0x7f608741f700) at pthread_create.c:308
#4  0x00007f60bcfb3cbd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f60c152c780 (LWP 21865)):
[KCrash Handler]
#6  0x00007f60bcef6425 in __GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#7  0x00007f60bcef9b8b in __GI_abort () at abort.c:91
#8  0x00007f60be75150b in qt_message_output(QtMsgType, char const*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#9  0x00007f60be7518bf in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#10 0x00007f60be751a64 in qFatal(char const*, ...) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#11 0x00007f6096a49841 in Okular::DocumentPrivate::openDocumentInternal (this=0x1b9b160, offer=..., isstdin=false, docFile=..., filedata=...) at /home/inf0phile/kile-livepreview/src/okular/core/document.cpp:904
#12 0x00007f6096a5193d in Okular::Document::openDocument (this=0x1b33b30, docFile=..., url=..., _mime=...) at /home/inf0phile/kile-livepreview/src/okular/core/document.cpp:1996
#13 0x00007f6096d2409e in Okular::Part::openFile (this=0x1941030) at /home/inf0phile/kile-livepreview/src/okular/part.cpp:1203
#14 0x00007f60c02b499c in ?? () from /usr/lib/libkparts.so.4
#15 0x00007f60c02b4f54 in KParts::ReadOnlyPart::openUrl(KUrl const&) () from /usr/lib/libkparts.so.4
#16 0x00007f6096d1e028 in Okular::Part::openUrl (this=0x1941030, _url=...) at /home/inf0phile/kile-livepreview/src/okular/part.cpp:1353
#17 0x00000000005dfe31 in KileTool::LivePreviewManager::synchronizeViewWithCursor (this=0x27b8db0, textInfo=<optimized out>, view=<optimized out>, newPosition=..., calledFromCursorPositionChange=true) at /home/inf0phile/kile-livepreview/src/kile/src/livepreview.cpp:769
#18 0x00000000005e01e5 in KileTool::LivePreviewManager::handleCursorPositionChangedTimeout (this=0x27b8db0) at /home/inf0phile/kile-livepreview/src/kile/src/livepreview.cpp:728
#19 0x00007f60be86f281 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#20 0x00007f60be874179 in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#21 0x00007f60bd960894 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#22 0x00007f60bd965713 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#23 0x00007f60bf2c03f6 in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#24 0x00007f60be85ae9c in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#25 0x00007f60be88c1f2 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#26 0x00007f60be889c0d in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#27 0x00007f60be889c31 in ?? () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#28 0x00007f60b8c24d53 in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#29 0x00007f60b8c250a0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#30 0x00007f60b8c25164 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#31 0x00007f60be88a3bf in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#32 0x00007f60bda08d5e in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4
#33 0x00007f60be859c82 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#34 0x00007f60be859ed7 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#35 0x00007f60be85ef67 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQtCore.so.4
#36 0x000000000043c7bd in main (argc=1, argv=0x7fff6e03ffe8) at /home/inf0phile/kile-livepreview/src/kile/src/main.cpp:150

OK I fixed the bug. I had to install the library poppler ! BEFORE installing okular and kile as describe here (http://sourceforge.net/apps/mediawiki/kile/index.php?title=Live_Preview)

Here is the way I found the solution :

* The backtrace shows that the error occurs in the file documents.cpp in function Okular::DocumentPrivate::openDocumentInternal, and it is raised by the line 904 : 

Q_ASSERT_X( m_generator, "Document::load()", "null generator?!" );"

What means that the pointer m_generator is NULL !

* The generator is given by the function DocumentPrivate::loadGeneratorLibrary, and more precisily by this line : 

Generator * generator = factory->create< Okular::Generator >( service->pluginKeyword(), 0 ); 

I put a "cout" to display the variable service->pluginKeyword(), which was empty ! So a plugin was missing. In order to know which one is missing, I printed the variable service->name(), I understood it is about the plugin "Poppler". Indeed I noticed the folder "poppler" didn't appear in the folder "generators" of build_okular while it was in the folder "generators" of the sources ! It seems that Poppler has not been installed, and indeed when I checked the "Makefile" (generated by cmake) I noticed that there was no target for the librairy "Poppler". 

* I have installed "Poppler" (as it was actually recommended here : http://okular.kde.org/download.php ) downloading the latest version here : http://poppler.freedesktop.org/

* I try again to install okular and kile : http://sourceforge.net/apps/mediawiki/kile/index.php?title=Live_Preview

I noticed during the cmake (in the debug mode) that Poppler was sucessfully founded, and during the installation (make install -j 2) that the okularGenerator_poppler.so was treated too!

* I launched ./run.sh (which contains now the lines export for Poppler as explained here http://okular.kde.org/download.php ) and it works !!!