Troubleshooting
This document contains solutions for known problems when running Retool on supported operating systems.
SSL: CERTIFICATE_VERIFY_FAILED error
If you see the error[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate
when trying to download files in Retool, it's a
shortcoming in the way Python's SSL module is designed
that prevents it from obtaining the certificates it needs to verify that it can trust
the secure website it wants to download from.
The easiest way to work around this is to install OpenSSL and import the Mozilla CA certificate store:
-
Download OpenSSL (the light version is fine), and then run the installer.
Note
You might be prompted to download and install a Visual C++ redistributable as part of the OpenSSL installation process. Do so. The redistributable downloads to your default download directory, and you should install it before continuing the OpenSSL installation.
-
Complete the OpenSSL install.
-
Open Windows PowerShell as an administrator.
-
Run the following script to download and import the Mozilla CA certificate store:
cd $env:USERPROFILE; Invoke-WebRequest https://curl.se/ca/cacert.pem -OutFile $env:USERPROFILE\cacert.pem; $plaintext_pw = 'PASSWORD'; $secure_pw = ConvertTo-SecureString $plaintext_pw -AsPlainText -Force; & 'C:\Program Files\OpenSSL-Win64\bin\openssl.exe' pkcs12 -export -nokeys -out certs.pfx -in cacert.pem -passout pass:$plaintext_pw; Import-PfxCertificate -Password $secure_pw -CertStoreLocation Cert:\LocalMachine\Root -FilePath certs.pfx;
Retool should now be able to download the files it needs.
SSL: CERTIFICATE_VERIFY_FAILED error
If you see the error[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate
when trying to download files in Retool, it's a
shortcoming in the way Python's SSL module is designed
that prevents it from obtaining the certificates it needs to verify that it can trust
the secure website it wants to download from.
To work around this, run the following commands, which download the required
certificates into your home folder and then add them to your system keychain. Replace
PYTHON_VERSION with the major.minor version of your
Python install. For example, for Python 3.14.0, use 3.14.
curl -o ~/cacert.pem https://curl.se/ca/cacert.pem
awk '/-----BEGIN CERTIFICATE-----/{flag=1} flag{print} /-----END CERTIFICATE-----/{exit}' ~/cacert.pem > ~/first-cert.pem
sudo security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain ~/first-cert.pem
open "/Applications/Python PYTHON_VERSION/Install Certificates.command"