We had earlier saved the getLocalizedText() OOTB function in our application specific library and ruleset. We do not need any more, but after deleting the function from our application specific library and ruleset, all sections, including rule forms in the developer portal are failing to open as it is still looking for getLocalizedText() function in the application library and ruleset.
We have recompiled all libraries from SMA but that has not helped.
It seems like the section could have been compiled with the reference to your function in it. Can you test resaving one of the sections to see if the error goes away for that section? Also, what version are you using?