For any extensions Firefox 69+, create
extensions.checkCompatibility.nightly false
extensions.checkUpdateSecurity false
For plugins, create
plugin.load_flash_only false
The browser only looks for application/x-shockwave-flash , it is necessary to correct the plugin and script, example https://dl.dropboxusercontent.com/s/xv8i6fbojvbxlqd/vmp.JPG
or wait for a new version of MyPal with a fixed NPAPI
if ublock crashes, old version 1.16.20 https://addons.mozilla.org/firefox/downloads/file/1056733/ublock_origin-1.16.20-an+fx.xpi