For now, you can create a new profile under K-Meleon. in the Profile manager chechk for asking the profile. By default it purpose the last you have used. So, the only problem will be to have to press enter to continue with your usual profile.
Don't use the new one, except perhaps to complete its creation.
After, when you'll have the problem again, try to open the new profile instead of the usual one.
If it works, it's your profile which is bad, else perhaps a windows or other thing problem.
It's perhaps not the answer you were waiting for, but I have nothing else.
Perhaps somebody else ?
Mozilla/5.0 (x11; U; Linux x86_64; fr-FR; rv:38.0) Gecko/20100101 Ubuntu/12.04 K-Meleon/76.0
Mail : alain [dot] aupeix [at] wanadoo [dot] fr
Ubuntu 12.04 - Gramps 3.4.9 - Harbour 3.2.0 - Hwgui 2.20-3 - K-Meleon 76.0 rc