Hi,

please check if these answers help you:

https://support.mozilla.org/en-US/questions/1206824 https://support.mozilla.org/en-US/questions/1208635

You could also try to update to a newer version of Firefox.

No help. Tried safe-mode and all the add-ons disabled, no modified settings on address bar either(all three enabled).

 Current(69.0.2) firefox core dumps with SIGILL - illegal instruction, this is the last version(52.0) i could get working on AMD K7 machine.
 And on the other hand, used web-pages wont work on any other browser, so trying to manage with this one.
 Here are some backtrace logs, if helpful:
 

$ firefox --debug GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1 Copyright (C) 2016 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i686-linux-gnu". Type "show configuration" for configuration details. For bug reporting instructions, please see: <http://www.gnu.org/software/gdb/bugs/>. Find the GDB manual and other documentation resources online at: <http://www.gnu.org/software/gdb/documentation/>. For help, type "help". Type "apropos word" to search for commands related to "word"... Reading symbols from /usr/lib/firefox/firefox...(no debugging symbols found)...done. (gdb) r Starting program: /usr/lib/firefox/firefox [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".

Program received signal SIGILL, Illegal instruction. 0x0044b958 in mozilla::TimeStamp::Now(bool) () (gdb) bt

1. 0 0x0044b958 in mozilla::TimeStamp::Now(bool) ()
2. 1 0x00407b1d in ?? ()
3. 2 0x0046d98b in __libc_csu_init ()
4. 3 0xb7bfe5c7 in __libc_start_main (main=0x407d80 <_start+539>, argc=1,

   argv=0xbffff504, init=0x46d940 <__libc_csu_init>, 
   fini=0x46d9a0 <__libc_csu_fini>, rtld_fini=0xb7fea880 <_dl_fini>, 
   stack_end=0xbffff4fc) at ../csu/libc-start.c:247

1. 4 0x00407b96 in _start ()

(gdb)

Have you changed history expiration settings by any chance? If so, and if your browser history was huge, that could cause a significant delay when pressing return key.

If not; newer Firefox versions no longer support your hardware. So even reporting a bug here would not help, since in the best case it would get fixed in a future version. Also there are similar bugs reported and fixed in later versions. For example this one was reported for v. 52 and fixed in v. 60.

So you might be out of luck. At least I'm out of ideas :(

You nailed it! Wasn't in any kind of high hopes anymore, but tried anyways clear all kinds of history. Works like a charm now. And I even got almost 4 gigs of free disk space too! Thanks :)