I got this error warning while I was trying to install filedtrip:
Error using websave (line 98)
Could not establish a secure connection to "download.fieldtriptoolbox.org". The reason is "error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed". Check your certificate file (C:\Program Files\MATLAB\R2018b\sys\certificates\ca\rootcerts.pem) for expired, missing or invalid certificates.
** Error: An error occurred while updating plugin fieldtrip:
** Impossible to download fieldtrip automatically:
** websave and urlwrite failed reading URL: https://download.fieldtriptoolbox.org/fieldtrip-lite-20220228.zip
** Error using websave (line 98)
** Could not establish a secure connection to "download.fieldtriptoolbox.org". The reason is "error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed". Check your certificate file (C:\Program Files\MATLAB\R2018b\sys\certificates\ca\rootcerts.pem) for expired, missing or invalid certificates.
** Alternative download solution:
** 1) Copy the URL below from the Matlab command window:
** https://download.fieldtriptoolbox.org/fieldtrip-lite-20220228.zip
** 2) Paste it in a web browser
** 3) Save the file and unzip it
** 4) Add to the Matlab path the folder containing ft_defaults.m.
**
