I am using CiviCRM for 6 months now and suddenly, since a couple of weeks when I try to enter or change an address I get a pop up saying "Netwerkfout Geen verbinding met de server. Ververs deze pagina in uw webbrowser en probeer het opnieuw." The web-console reports "Unchecked lastError value: Error: Could not establish connection. Receiving end does not exist. background-index.js:1 createSyncMiddleware moz-extension://51240b76-34de-491a-a81e-3e49bd7d7805/background-index.js:1:623946". I can change other member fields, though.
I followed all instructions on https://docs.civicrm.org/dev/en/latest/tools/debugging/ , and also tried different browsers, with plug-ins switched off.
I am still running CiviCRM 4.6.38, and I notice that my provider is still running MySQL v5.0.95 (and not very willing to upgrade). Latest WordPress version.
Any hints on how I could solve this problem?