The problem seems to be, that the manager tries to check for package updates by calling the API https://rest.modx.com/extras/package/update?...&signature=getdate-1.0.0-pl....
But for some reason the API returns an error for the getDate package
<error>
<success>false</success>
<message>No Package release found.</message>
<object/>
<status>404</status>
<description>
No published versions of the Package could be found supporting your environment.
</description>
</error>
and this is not handled gracefully by the code.
As a temporary fix, you could also just change the value of the column “provider” to 0 for the offending row in the database table modx_transport_packages (instead of deleting the whole row).
This should prevent the code from checking for updates.