[JavaScript Error: "Could not remove C:\Users\[…]\AppData\Roaming\Microsoft\Word\STARTUP\Zotero.dotm"

This is likely due to security software on your computer preventing Zotero from updating the Word plugin. You may need to do a manual installation. See here:

https://www.zotero.org/support/word_processor_plugin_troubleshooting#error_or_non-responsive_plugin_buttons