Firefox may reinitialize its certificate store after an update, in this case you can reinstall it by opening the Downloader and going to Detection> Reinstall HTTPS/SSL.
The certificate Database can be corrupted in this case try to install it manually by following this guide:
https://wiki.wmtransfer.com/projects/we ... la_Firefox
You will find the certificate to import in your computer, at the following path :
C:\Program Files (x86)\VSO\VSO Downloader\5\certificate\ca_sha2.crt
Firefox HTTPS support - help, tips and troubleshooting
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Firefox HTTPS support - help, tips and troubleshooting
Last edited by Jacques (VSO) on Fri May 24, 2019 2:50 pm, edited 2 times in total.
Reason: Clarification - screenshot added
Reason: Clarification - screenshot added