It is necessary to also obtain a new license file and manually place it in the root/Thingworx directory. Please refer to the more detailed steps outlined in the 'Installing ThingWorx 8.0' guide:
"..3. If you have not already done so, create a folder called ThingworxPlatform at the root of the drive where Tomcat was installed. NOTE: Ensure the ThingWorx server has Read and Write access to the ThingworxPlatform and ThingworxStorage folders. Without these permissions, the server will fail to start.
4. Obtain the license.bin file from the PTC Support site:
a. Log into the PTC Support site.
b. Click Manage Licenses.
c. Click PTC ThingWorx>PTC Licensing Tool.
d. Click Download.
5. Rename the file to license.bin and place it in the ThingworxPlatform folder. NOTE: Failure to place the license.bin in the ThingworxPlatform folder will result in ThingWorx not starting after deployment."
6. After following these steps, be sure to close the Composer window and restart Tomcat.
Do you find you are still seeing the same error?
Okay, yes I can see I overlooked that the license was already present.
Please confirm, did you import both extensions? (ThingworxManufacturingApps-8.0.0-00-extension-dependencies.zip and ThingworxManufacturingApps-8.0.0-00-extension.zip)
Have you closed the Composer window and restarted Tomcat?
Technical Support Engineer | Kepware Technologies
What user are you currently logged in as? I would recommend logging in as the default "Administrator" user, as any other users (specifically the ones created by you) will not have access to the apps unless you add them to the "Controls Engineer," "Production Manager," or "Maintenance Engineer" groups.