network.protocol-handler.external-default. is set to true and other 

I am running the latest update of Thunderbird 128.4.0 When I try to insert a link over text. Thunderbird hangs. I do not have any addons so there is nothing to disable. HOWEVER when I run Thunderbird in Troubleshoot mode with the button for addons disabled --- everything works as it should! I start in regular mode and look for invisible add ons to disable but there are no add ons and no themes. I have gone to the Trouble shoot information page. I looked at the Important modified preferences to see if any network protocol handler was set to false but there are none. I went to about.config and found several preferences network.protocol-handler.external-default. is set to true and other preferences beginning with network.protocol-handler.warn-external. were set to false. Forums said to set them to true to resolve problem. I did that but it did not help. I have cleared my cache because - why not! I stress that if I run in troubleshoot mode things work. I have been using Thunderbird for 10 years and recently jumped from version 65 to version 128. I do not know when the insert link stopped working. Any ideas besides uninstall reinstall? SOLVED I cleared my startup cache and that did the trick.