installing paramiko upgrades the cryptography to the latest version which is not compatiable with odoo15. 

Odoo15 works with cryptography==2.6.1  as there is incompatibility between pyopenssl 19.0.0 and cryptography>=37.0.0. (You can see this in the requirements.txt while installing odoo15)

Install a lower version of paramiko. I have installed paramiko version 2.12.0 (pip install paramiko==2.12.0) and have no issues.

stalling Paramiko in Odoo 15 should not cause any issues by itself, as it is a common library for SSH connections that does not directly interact with Odoo. However, if you are experiencing problems with Odoo after installing Paramiko, it may be due to other factors.

Here are some steps you can try to diagnose and resolve the issue:

1. Check the Odoo server logs:

Check the Odoo server logs for any error messages that may be related to the issue. You can find the logs in the Odoo installation directory under the "logs" folder. Look for any error messages related to Paramiko or SSH connections.

1. Check the installed Python packages:

Check the installed Python packages to make sure there are no conflicts or missing dependencies. You can check the installed packages using pip or the package manager of your operating system.

1. Check the installed Odoo modules:

Check the installed Odoo modules to make sure there are no conflicts or missing dependencies. You can check the installed modules in Odoo by going to Settings > Installed Modules.

1. Try disabling the Paramiko module:

If you suspect that the issue is related to the Paramiko module, try disabling it and see if the problem persists. You can disable the module by commenting out the line that installs it in the requirements.txt file of your Odoo installation, or by removing it from the list of installed Python packages.

1. Try reinstalling Odoo:

If none of the above steps work, try reinstalling Odoo from scratch. This will ensure that all dependencies are installed correctly and there are no conflicts with previously installed packages.

Keep in mind that these steps are just general suggestions and may not solve your specific issue. If you continue to experience problems with Odoo, you may need to seek help from a developer or a support forum.