I discovered this error when trying to determine why the tax rates were not working. The taxrate plugin was installed in 3.8, but after updating, became uninstalled.
When trying to install it again from the plugins menu, I get the "There is already an object named 'TaxRate' in the database." message. (NOTE: I have the same problem with the flat rate shipping).
The plug-in is in the correct folder.
Group: Tax providers
FriendlyName: Manual (Fixed or By Country/State/Zip)
SystemName: Tax.FixedOrByCountryStateZip
Version: 1.00
SupportedVersions: 3.90
Author: nopCommerce team
DisplayOrder: 1
FileName: Nop.Plugin.Tax.FixedOrByCountryStateZip.dll
Description: This plugin allow to configure fix tax rates or tax rates by coutries, states and zip codes
I've rebuilt the solution and verified the build, so I'm at a loss as what to do (or where in the database this info is stored)
Help!