I had the same issue for a long time in 14.04 at least together with kernel 4.2 (and very likely 3.19 and maybe even before if I remember right).
It is still not fixed in ubuntu 16.04, kernel 4.4.0-28-generic. I get this problem mostly after suspend. But I rarely get the invisible characters also during a normal session when I click something (about every few days). I could not yet reproduce if it depends on the object I click or if there is a pattern to reproduce it. Tested hardware: Latitude E5510, CPU/GPU Intel core i5 520M, using the on-chip graphics. I have an PR02X docking station and a dual monitor setup (2x external BenQ GW2460 via DVI) when this error happens. The problem does not occor when using the internal monitor of the laptop only. Please note that my on-chip-GPU can handle two monitors only. Basically that means that the internal monitor is switched off automatically as soon as I use the two external monitors. So far this is working fine, however. uname -a Linux lat61 4.4.0-28-generic #47-Ubuntu SMP Fri Jun 24 10:09:13 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1528843 Title: Fonts missing after suspend To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1528843/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
