Does post #59 match your issue?

rbarbour proposed 2 things to try.
soxophoneplayer also posted something to try.
Are you using the DIY install of Flexible Footer or built into a template? Now I am confused and the 2 versions may or may not be the same.

I am not a coder. Just read a lot.

There just seems to be quite a bit of issues of v155a not playing nice with various plugins and templates and it just scared the carp out of me to even think about beginning an upgrade.