Since upgrade to Thunderbird Version 60.5.0, all Microsoft Attachments open with a "corrupt file" and then repair which eventually open except for Visio

Since upgrade to Thunderbird Version 60.5.0, all Microsoft Attachments (xlsx, ppt, docx, vsdx) open with a "corrupt file" and then repair which eventually open except for Visio which seem completely corrupt. If I use company webmail or even Outlook, the same files open fie from those clients. On forum one possible solution is to download and install https://taskcluster-artifacts.net/AcRd5mSOROO3yWDvEyrmSQ/0/public/build/install/sea/target.installer.exe, but I'm not allowed to install this per company rules due to no authenticated certificate. Warning on install states "this file does not have a digital signature which verifies publisher". Should I uninstall and revert back to an earlier version or will this be fixed soon without users having to do workarounds on their own? Thanks, Steve