PERFORMANCE WARNING: Search service falling back to synchronous initialization. This is generally the consequence of an add-on using a deprecated search service API.
You may find more details about this problem at: https://developer.mozilla.org/en-US/docs/XPCOM_Interface_Reference/nsIBrowserSearchService#async_warning
Callstack:
resource://gre/components/nsSearchService.js 2882 SRCH_SVC__ensureInitialized
resource://gre/components/nsSearchService.js 3929 SRCH_SVC_getVisible
chrome://custombuttons-context/content/button.js?windowId=Firefox&id=custombuttons-button12@init line 1 > Function 23 setItemsToMenuPopup
chrome://custombuttons-context/content/button.js?windowId=Firefox&id=custombuttons-button12@init line 1 > Function 33 anonymous
chrome://custombuttons-context/content/button.js?windowId=Firefox&id=custombuttons-button12@init 1 null
chrome://custombuttons/content/cbbutton.js 281 buttonCbExecuteCode
chrome://custombuttons/content/cbbutton.js 113 buttonInit
chrome://custombuttons/content/cbbuttonimpl.js 4 init
chrome://custombuttons/content/cbbutton.js 70 buttonConstructor/<