Title: FAQ — UCS Tools Documentation URL Source: https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html Published Time: Thu, 30 Oct 2025 07:23:03 GMT Markdown Content: FAQ[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#faq "Link to this heading") --------------------------------------------------------------------------------------- The app build command seems to be stuck?[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#the-app-build-command-seems-to-be-stuck "Link to this heading") ---------------------------------------------------------------------------------------------------------------------------------------------------------------- * If the app uses services whose Helm charts are remotely hosted (e.g., NGC Helm registry), it takes longer to fetch the Helm charts compared to when the Helm charts are on the local filesystem. Failed to load/export parameters of a graph[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#failed-to-load-export-parameters-of-a-graph "Link to this heading") ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- * Save the graph before loading or exporting parameters. Unable to delete a backdrop[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#unable-to-delete-a-backdrop "Link to this heading") --------------------------------------------------------------------------------------------------------------------------------------- * 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[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#graph-is-broken-after-sync-up-from-the-registry "Link to this heading") ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- * Close the graph before syncing. Application builder CLI hangs[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#application-builder-cli-hangs "Link to this heading") ------------------------------------------------------------------------------------------------------------------------------------------- * Make sure UCS Studio is not running on the same system. UCS Studio holds registry cache DB lock which prevents CLI tool from accessing registry. Close UCS Studio as a workaround. Unable to run WebSocket streaming with UCS Studio[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#unable-to-run-websocket-streaming-with-ucs-studio "Link to this heading") ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- * WebSocket Streaming is no longer supported. Can I change the default paths for registry and config?[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#can-i-change-the-default-paths-for-registry-and-config "Link to this heading") ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 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 Ensure the directories exist and you have sufficient permissions. CLI `service list` operations do not seem to do anything[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#cli-service-list-operations-do-not-seem-to-do-anything "Link to this heading") ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- This can happen if the **local** repository does not have any microservices and **NGC** repositories have not been added using the [registry repo set-api-key](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_AppBuilder.html#appbuilder-cli-set-api-key) command. Once either of the two happens, the `service list` command will list all available microservices from **local** and/or **NGC** repositories. CLI `service sync` command fails with error “An unhandled error occurred!”[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#cli-service-sync-command-fails-with-error-an-unhandled-error-occurred "Link to this heading") -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Use one of these alternatives: * Use the [service versions](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_AppBuilder.html#appbuilder-cli-sevice-versions) command to get a list of available versions for the microservice. Use `ucf_app_builder_cli service sync -n -v ` to sync a specific version of the microservice. * Use the [repo sync](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_AppBuilder.html#appbuilder-cli-sevice-versions) command to sync the latest versions of all microservices. * Use the [Repo Sync](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_Studio.html#ucf-studio-repo-sync) functionality of **UCS Studio**. `repo sync` operation fails for **local** repository[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#repo-sync-operation-fails-for-local-repository "Link to this heading") ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- This is expected since the `repo sync` operation is not supported for **local** repository. Parameters file exported from **UCS Studio** does not work[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#parameters-file-exported-from-ucs-studio-does-not-work "Link to this heading") ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- If parameters for multiple microservices are exported using **UCS Studio**, you cannot load them again in **UCS Studio** or with **UCS AppBuilder CLI**. To make the file work, remove the `---` YAML doc separators from the file. Uninstall UCS Tools[#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#uninstall-ucs-tools "Link to this heading") ----------------------------------------------------------------------------------------------------------------------- To uninstall UCS Tools, run: sudo apt remove ucf-tools # if version < 2.5 sudo apt remove ucs-tools # if version >= 2.5 Note DO NOT run `sudo apt remove ucf`. `ucf` is a Linux utility to `update configuration file` to incorporate user’s changes. Removing this will break your system. Links/Buttons: - [#](https://docs.nvidia.com/ucf/2.10.0/text/UCS_FAQ.html#uninstall-ucs-tools) - [registry repo set-api-key](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_AppBuilder.html#appbuilder-cli-set-api-key) - [service versions](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_AppBuilder.html#appbuilder-cli-sevice-versions) - [Repo Sync](https://docs.nvidia.com/ucf/2.10.0/text/tools_reference/UCS_Tools_Reference_Studio.html#ucf-studio-repo-sync)