SUMMARY
Crash at startup, most of the time after cold boot. Possible duplicate of certain bugs, but it's slightly different from those i checked.

STEPS TO REPRODUCE
1. Turn on the computer

OBSERVED RESULT

Baloo crash

EXPECTED RESULT

Baloo works

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 5.15.2
KDE Frameworks Version: 5.56.0
Qt Version: 5.11.3


ADDITIONAL INFORMATION
Application: Baloo File Indexing Daemon (baloo_file), signal: Segmentation fault
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
__GI___libc_read (nbytes=16, buf=0x7ffe0006b9e0, fd=3) at ../sysdeps/unix/sysv/linux/read.c:26
[Current thread is 1 (Thread 0x7f43f5a5d080 (LWP 1709))]

Thread 3 (Thread 0x7f03effff700 (LWP 2118)):
[KCrash Handler]
#6  0x00007f43f89aadb4 in mdb_midl_xmerge () from /usr/lib/x86_64-linux-gnu/liblmdb.so.0
#7  0x00007f43f89a2335 in ?? () from /usr/lib/x86_64-linux-gnu/liblmdb.so.0
#8  0x00007f43f89a4434 in ?? () from /usr/lib/x86_64-linux-gnu/liblmdb.so.0
#9  0x00007f43f89a4818 in ?? () from /usr/lib/x86_64-linux-gnu/liblmdb.so.0
#10 0x00007f43f89a7c01 in mdb_cursor_put () from /usr/lib/x86_64-linux-gnu/liblmdb.so.0
#11 0x00007f43f89aa2db in mdb_put () from /usr/lib/x86_64-linux-gnu/liblmdb.so.0
#12 0x00007f43fa40315c in Baloo::PostingDB::put(QByteArray const&, QVector<unsigned long long> const&) () from /usr/lib/x86_64-linux-gnu/libKF5BalooEngine.so.5
#13 0x00007f43fa4137dd in Baloo::WriteTransaction::commit() () from /usr/lib/x86_64-linux-gnu/libKF5BalooEngine.so.5
#14 0x00007f43fa409a82 in Baloo::Transaction::commit() () from /usr/lib/x86_64-linux-gnu/libKF5BalooEngine.so.5
#15 0x0000560fc71cd0f5 in ?? ()
#16 0x00007f43f9eb1f91 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007f43f9eb9c77 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007f43f8a0b182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#19 0x00007f43f99f9faf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 2 (Thread 0x7f43f524a700 (LWP 1715)):
#0  0x00007f43f99edba9 in __GI___poll (fds=0x7f43f0005260, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1  0x00007f43f8345c76 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007f43f8345d9c in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f43fa0b404b in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#4  0x00007f43fa06114b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5  0x00007f43f9eb00d6 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6  0x00007f43fa435545 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5DBus.so.5
#7  0x00007f43f9eb9c77 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f43f8a0b182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#9  0x00007f43f99f9faf in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 1 (Thread 0x7f43f5a5d080 (LWP 1709)):
#0  __GI___libc_read (nbytes=16, buf=0x7ffe0006b9e0, fd=3) at ../sysdeps/unix/sysv/linux/read.c:26
#1  __GI___libc_read (fd=3, buf=0x7ffe0006b9e0, nbytes=16) at ../sysdeps/unix/sysv/linux/read.c:24
#2  0x00007f43f838c510 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007f43f834574f in g_main_context_check () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007f43f8345c20 in ?? () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007f43f8345d9c in g_main_context_iteration () from /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#6  0x00007f43fa0b4033 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7  0x00007f43fa06114b in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8  0x00007f43fa0692b2 in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9  0x0000560fc71c7997 in ?? ()
#10 0x00007f43f9902b6b in __libc_start_main (main=0x560fc71c7610, argc=1, argv=0x7ffe0006bf78, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7ffe0006bf68) at ../csu/libc-start.c:308
#11 0x0000560fc71c7b3a in ?? ()
[Inferior 1 (process 1709) detached]