diff --git a/pkg/c8yfetcher/c8yfetcher.go b/pkg/c8yfetcher/c8yfetcher.go
index c7968c397..0fc8140d8 100644
--- a/pkg/c8yfetcher/c8yfetcher.go
+++ b/pkg/c8yfetcher/c8yfetcher.go
@@ -130,8 +130,10 @@ func lookupEntity(fetch EntityFetcher, values []string, getID bool, format strin
 						Data: resultSet,
 					})
 				}
+			} else {
+				// Propagate errors back to the caller
+				return entities, err
 			}
-			// TODO: Handle error
 		} else {
 			entities = append(entities, entityReference{
 				ID: applyFormatter(id, format),
@@ -150,8 +152,10 @@ func lookupEntity(fetch EntityFetcher, values []string, getID bool, format strin
 					Data: resultSet,
 				})
 			}
+		} else {
+			// Propagate errors back to the caller
+			return entities, err
 		}
-		// TODO: Handle error
 	}
 
 	return entities, nil
diff --git a/pkg/c8yfetcher/childAdditionFetcher.go b/pkg/c8yfetcher/childAdditionFetcher.go
index 54a848800..f98979d4f 100644
--- a/pkg/c8yfetcher/childAdditionFetcher.go
+++ b/pkg/c8yfetcher/childAdditionFetcher.go
@@ -2,6 +2,7 @@ package c8yfetcher
 
 import (
 	"context"
+
 	"github.com/pkg/errors"
 	"github.com/reubenmiller/go-c8y/pkg/c8y"
 )
@@ -41,9 +42,13 @@ func (f *ChildAdditionFetcher) getByID(id string) ([]fetcherResultSet, error) {
 }
 
 func (f *ChildAdditionFetcher) getByName(name string) ([]fetcherResultSet, error) {
+	var err error
 	query := "name eq '" + name + "'"
 	if f.Query != nil {
-		query = f.Query(name)
+		query, err = f.Query(name)
+		if err != nil {
+			return nil, NewQueryBuildErr(err)
+		}
 	}
 	mcol, _, err := f.client.Inventory.GetChildAdditions(
 		c8y.WithDisabledDryRunContext(context.Background()),
diff --git a/pkg/c8yfetcher/configurationFetcher.go b/pkg/c8yfetcher/configurationFetcher.go
index d3f028b78..422e2524a 100644
--- a/pkg/c8yfetcher/configurationFetcher.go
+++ b/pkg/c8yfetcher/configurationFetcher.go
@@ -16,8 +16,8 @@ func NewConfigurationFetcher(factory *cmdutil.Factory) *ConfigurationFetcher {
 			CumulocityFetcher: &CumulocityFetcher{
 				factory: factory,
 			},
-			Query: func(s string) string {
-				return fmt.Sprintf("(type eq 'c8y_ConfigurationDump') and name eq '%s'", s)
+			Query: func(s string) (string, error) {
+				return fmt.Sprintf("(type eq 'c8y_ConfigurationDump') and name eq '%s'", s), nil
 			},
 		},
 	}
diff --git a/pkg/c8yfetcher/deviceServiceFetcher.go b/pkg/c8yfetcher/deviceServiceFetcher.go
index f7510eb61..8a987b585 100644
--- a/pkg/c8yfetcher/deviceServiceFetcher.go
+++ b/pkg/c8yfetcher/deviceServiceFetcher.go
@@ -18,11 +18,11 @@ func NewDeviceServiceFetcher(factory *cmdutil.Factory, device string) *DeviceSer
 			CumulocityFetcher: &CumulocityFetcher{
 				factory: factory,
 			},
-			Query: func(s string) string {
+			Query: func(s string) (string, error) {
 
 				client, err := factory.Client()
 				if err != nil {
-					return ""
+					return "", err
 				}
 
 				if !IsID(device) {
@@ -30,15 +30,18 @@ func NewDeviceServiceFetcher(factory *cmdutil.Factory, device string) *DeviceSer
 					moDevice, _, err := client.Inventory.GetDevicesByName(c8y.WithDisabledDryRunContext(context.Background()), device, &c8y.PaginationOptions{
 						PageSize: 5,
 					})
-					if err == nil && moDevice != nil && len(moDevice.ManagedObjects) > 0 {
+					if err != nil {
+						return "", NewQueryBuildErr(err)
+					}
+					if moDevice != nil && len(moDevice.ManagedObjects) > 0 {
 						device = moDevice.ManagedObjects[0].ID
 					}
 				}
 
 				if IsID(device) {
-					return fmt.Sprintf("(type eq 'c8y_Service') and name eq '%s' and (bygroupid(%s))", s, device)
+					return fmt.Sprintf("(type eq 'c8y_Service') and name eq '%s' and (bygroupid(%s))", s, device), nil
 				}
-				return fmt.Sprintf("(type eq 'c8y_Service') and name eq '%s'", s)
+				return fmt.Sprintf("(type eq 'c8y_Service') and name eq '%s'", s), nil
 			},
 		},
 	}
diff --git a/pkg/c8yfetcher/firmwareFetcher.go b/pkg/c8yfetcher/firmwareFetcher.go
index 932615ea5..10f38ebe2 100644
--- a/pkg/c8yfetcher/firmwareFetcher.go
+++ b/pkg/c8yfetcher/firmwareFetcher.go
@@ -16,8 +16,8 @@ func NewFirmwareFetcher(factory *cmdutil.Factory) *FirmwareFetcher {
 			CumulocityFetcher: &CumulocityFetcher{
 				factory: factory,
 			},
-			Query: func(s string) string {
-				return fmt.Sprintf("(type eq 'c8y_Firmware') and name eq '%s'", s)
+			Query: func(s string) (string, error) {
+				return fmt.Sprintf("(type eq 'c8y_Firmware') and name eq '%s'", s), nil
 			},
 		},
 	}
diff --git a/pkg/c8yfetcher/firmwareVersionFetcher.go b/pkg/c8yfetcher/firmwareVersionFetcher.go
index c2b152d86..fa963cf25 100644
--- a/pkg/c8yfetcher/firmwareVersionFetcher.go
+++ b/pkg/c8yfetcher/firmwareVersionFetcher.go
@@ -18,18 +18,25 @@ func NewFirmwareVersionFetcher(factory *cmdutil.Factory, firmware string, includ
 			CumulocityFetcher: &CumulocityFetcher{
 				factory: factory,
 			},
-			Query: func(s string) string {
+			Query: func(s string) (string, error) {
 				client, err := factory.Client()
 				if err != nil {
-					return ""
+					return "", err
 				}
-				var firmwareID string
+
+				// Use default value of a non-existent id so that the query does not return anything
+				// Use a default (non-existent) managed object to ensure the inventory
+				// query is still valid when the firmware is not found (for whatever reason)
+				firmwareID := "0"
 				if IsID(firmware) {
 					firmwareID = firmware
 				} else {
 					// Lookup firmware by name
 					res, _, err := client.Firmware.GetFirmwareByName(c8y.WithDisabledDryRunContext(context.Background()), firmware, c8y.NewPaginationOptions(5))
-					if err == nil && len(res.ManagedObjects) > 0 {
+					if err != nil {
+						return "", NewQueryBuildErr(err)
+					}
+					if len(res.ManagedObjects) > 0 {
 						firmwareID = res.ManagedObjects[0].ID
 					}
 				}
@@ -39,7 +46,7 @@ func NewFirmwareVersionFetcher(factory *cmdutil.Factory, firmware string, includ
 					patchFilter = "not(" + patchFilter + ")"
 				}
 
-				return fmt.Sprintf("(type eq 'c8y_FirmwareBinary') and %s and c8y_Firmware.version eq '%s' and (bygroupid(%s))", patchFilter, s, firmwareID)
+				return fmt.Sprintf("(type eq 'c8y_FirmwareBinary') and %s and c8y_Firmware.version eq '%s' and (bygroupid(%s))", patchFilter, s, firmwareID), nil
 			},
 		},
 	}
diff --git a/pkg/c8yfetcher/managedObjectFetcher.go b/pkg/c8yfetcher/managedObjectFetcher.go
index c5bb9ee70..190bd2b36 100644
--- a/pkg/c8yfetcher/managedObjectFetcher.go
+++ b/pkg/c8yfetcher/managedObjectFetcher.go
@@ -2,12 +2,17 @@ package c8yfetcher
 
 import (
 	"context"
+
 	"github.com/pkg/errors"
 	"github.com/reubenmiller/go-c8y-cli/v2/pkg/cmdutil"
 	"github.com/reubenmiller/go-c8y/pkg/c8y"
 )
 
-type QueryFilter func(string) string
+func NewQueryBuildErr(err error) error {
+	return errors.Wrap(err, "Fetcher could not build a query")
+}
+
+type QueryFilter func(string) (string, error)
 
 type ManagedObjectFetcher struct {
 	Query QueryFilter
@@ -43,9 +48,13 @@ func (f *ManagedObjectFetcher) getByID(id string) ([]fetcherResultSet, error) {
 }
 
 func (f *ManagedObjectFetcher) getByName(name string) ([]fetcherResultSet, error) {
+	var err error
 	query := "name eq '" + name + "'"
 	if f.Query != nil {
-		query = f.Query(name)
+		query, err = f.Query(name)
+		if err != nil {
+			return nil, errors.Wrap(err, "Fetcher could not build a valid query")
+		}
 	}
 	mcol, _, err := f.Client().Inventory.GetManagedObjects(
 		c8y.WithDisabledDryRunContext(context.Background()),
diff --git a/pkg/c8yfetcher/softwareFetcher.go b/pkg/c8yfetcher/softwareFetcher.go
index 75fd8b2c4..7521b826c 100644
--- a/pkg/c8yfetcher/softwareFetcher.go
+++ b/pkg/c8yfetcher/softwareFetcher.go
@@ -16,8 +16,8 @@ func NewSoftwareFetcher(factory *cmdutil.Factory) *SoftwareFetcher {
 			CumulocityFetcher: &CumulocityFetcher{
 				factory: factory,
 			},
-			Query: func(s string) string {
-				return fmt.Sprintf("(type eq 'c8y_Software') and name eq '%s'", s)
+			Query: func(s string) (string, error) {
+				return fmt.Sprintf("(type eq 'c8y_Software') and name eq '%s'", s), nil
 			},
 		},
 	}
diff --git a/pkg/c8yfetcher/softwareVersionFetcher.go b/pkg/c8yfetcher/softwareVersionFetcher.go
index e64b6f050..c434b5ced 100644
--- a/pkg/c8yfetcher/softwareVersionFetcher.go
+++ b/pkg/c8yfetcher/softwareVersionFetcher.go
@@ -18,11 +18,11 @@ func NewSoftwareVersionFetcher(factory *cmdutil.Factory, software string) *Softw
 			CumulocityFetcher: &CumulocityFetcher{
 				factory: factory,
 			},
-			Query: func(s string) string {
+			Query: func(s string) (string, error) {
 				// Check
 				client, err := factory.Client()
 				if err != nil {
-					return ""
+					return "", err
 				}
 
 				if !IsID(software) {
@@ -30,15 +30,18 @@ func NewSoftwareVersionFetcher(factory *cmdutil.Factory, software string) *Softw
 					moSoftware, _, err := client.Software.GetSoftwareByName(c8y.WithDisabledDryRunContext(context.Background()), software, &c8y.PaginationOptions{
 						PageSize: 5,
 					})
-					if err == nil && moSoftware != nil && len(moSoftware.ManagedObjects) > 0 {
+					if err != nil {
+						return "", NewQueryBuildErr(err)
+					}
+					if moSoftware != nil && len(moSoftware.ManagedObjects) > 0 {
 						software = moSoftware.ManagedObjects[0].ID
 					}
 				}
 
 				if IsID(software) {
-					return fmt.Sprintf("(type eq 'c8y_SoftwareBinary') and not(has(c8y_Patch)) and c8y_Software.version eq '%s' and (bygroupid(%s))", s, software)
+					return fmt.Sprintf("(type eq 'c8y_SoftwareBinary') and not(has(c8y_Patch)) and c8y_Software.version eq '%s' and (bygroupid(%s))", s, software), nil
 				}
-				return fmt.Sprintf("(type eq 'c8y_SoftwareBinary') and not(has(c8y_Patch)) and c8y_Software.version eq '%s'", s)
+				return fmt.Sprintf("(type eq 'c8y_SoftwareBinary') and not(has(c8y_Patch)) and c8y_Software.version eq '%s'", s), nil
 			},
 		},
 	}
diff --git a/pkg/mapbuilder/mapbuilder.go b/pkg/mapbuilder/mapbuilder.go
index 3b238bdf2..675fe86b1 100644
--- a/pkg/mapbuilder/mapbuilder.go
+++ b/pkg/mapbuilder/mapbuilder.go
@@ -1060,10 +1060,8 @@ func (b *MapBuilder) MarshalJSONObject() (body []byte, err error) {
 		Logger.Debugf("body iterator. path=%s, value=%s", it.Path, value)
 
 		if itErr != nil {
-			if itErr == io.EOF {
-				err = itErr
-				return
-			}
+			err = itErr
+			return
 		} else {
 			switch extInput := input.(type) {
 			case []byte: