User Agent: Mozilla/5.0 (X11; Linux i686; rv:57.0) Gecko/20100101 Firefox/57.0 SeaMonkey/2.54a1 Build ID: 20170812003001 Steps to reproduce: Occasionally Seamonkey truncates the address picklist in the location bar to one line as shown on the first screenshot. Note the incomplete scrollbar and the missing bottom border - it is not a single matching line but an incompletely rendered full-sized picklist. Not sure what triggers this behaviour but once triggered it becomes persistent - all future attempts to open this picklist show only the 1st line. Sometimes typing additional characters (showing a particular address?) restores the normal behaviour (the second screenshot - immediately after taking the first one I typed more characters of the address), again persistently, but again not sure about the exact cause. Quite an old bug, not 2.54-specific. Seen it only on linux although I use seamonkey on windows too.
The moz_favicons table no longer exists. You should see errros in the log pointing to it. This should only occur in a new profile. In a migrated pre 2.53 profile you only loose the favicons. Should be fixed with bug 1355780.
If the moz_favicons table is present it can't be bug 1355780.
So far didn't encounter it on Windows. Maybe it is linux specific.