Microsoft does not allow me to save documents and share them in oneDrive.

Try these checks in order:

1. Validate the Microsoft account If sharing emails fail or OneDrive will not let documents be shared, validate the account at https://account.live.com/reputationcheck. Also make sure the Microsoft account profile is complete and Terms of Use are accepted if prompted.
2. Check whether the file is in Personal Vault Files stored in Personal Vault cannot be shared. Move the file to a folder outside Personal Vault, then try sharing again.
3. Check OneDrive sharing limits Basic or “storage only” OneDrive has sharing limits. These limits reset after 24 hours.
4. Make sure OneDrive is running If the OneDrive desktop app is not running or not installed, sharing from File Explorer or Finder will not work. Open OneDrive and try again. Sharing from onedrive.com is still available.
5. If using Outlook.com to share After validating the account, open the Outlook.com People view, select a contact, edit any contact information, and save the change. This can help sharing by email. Changes can take up to 24 hours to take effect.
6. If this is a work or school account Sharing may be disabled or restricted by the organization. Contact the IT helpdesk, service desk, or admin.
7. If saving from Word, Excel, or PowerPoint shows “UPLOAD BLOCKED” Make sure the Microsoft 365 app is signed in with the same account that has permission to upload to that OneDrive location.

If the problem is specifically “unable to reach the server” while sharing from OneDrive or SharePoint, also check:

• the site’s access request settings
• whether Do not save encrypted pages to disk is enabled in Internet Options
• whether the folder being shared has reached the 50,000 item sharing limit

References:

• Unable to share OneDrive files
• Can't share OneDrive files from Outlook.com
• "UPLOAD BLOCKED" error when you save OneDrive-synced files in Microsoft 365 apps
• "Unable to reach the server" error when sharing files or folders in SharePoint or OneDrive