The app build command seems to be stuck?

  • If the app uses services whose helm charts are remotely hosted (e.g NGC helm registry) it takes longer time to fetch the helm charts as compared to if the helm charts are on the local filesystem.

Failed to load/export parameters of a graph

  • Ensure that the graph has been saved before loading or exporting parameters

Unable to delete a backdrop

  • Delete the nodes inside the backdrop first or move the nodes out of the backdrop before deleting it

Graph is broken after sync up from the registry

  • Ensure that graph is closed before sync

Application builder CLI hangs

  • Make sure UCF Studio is not running on the same system. UCF Studio holds registry cache DB lock which prevents CLI tool from accessing registry. Workaround is to close UCF Studio.

Unable to run WebSocket streaming with UCF Studio

  • WebSocket Streaming is no longer supported

Can I change the default paths for registry and config?

Yes you can change the paths.

export UCF_REGISTRY_ROOT=/your/desired/registry/path
export UCF_CONFIG_ROOT=/your/desired/config/path
# set api key again for this to take effect
ucf_ms_builder_cli registry repo set-api-key -a <YOUR_NGC_API_KEY>

Ensure the directories exist and you have sufficient permissions.

CLI service list operations do not seem to do anything

This can happen if local repository does not have any microservices and NGC repositories have not been added using registry repo set-api-key command.

Once either of the two happens, service list command will list all the available microservices from local and/or NGC repositories.

CLI service sync command fails with error “An unhandled error occured!”

One of the following alternatives can be used:

  • Use the service versions command to get a list of available versions for the microservice. Use ucf_app_builder_cli service sync -n <name> -v <version> to sync a specific version of the microservice

  • Use repo sync command to sync the latest versions of all microservices

  • Use Repo Sync functionality of UCF Studio

repo sync operation fails for local repository

This is expected since repo sync operation is not supported for local repository

Parameters file exported from UCF Studio does not work

If parameters for multiple microservices are exported using UCF Studio, it cannot be loaded again in UCF Studio or with UCF AppBuilder CLI. To make the file work, remove the --- yaml doc separators from the file.

Uninstall UCF Tools

To uninstall UCF Tools, please run:

sudo apt remove ucf-tools


DO NOT run sudo apt remove ucf. ucf is an linux’s utility to update configuration file to incorporate user’s changes. Removing this will break your system.