diff --git a/routers/api/v1/admin/user.go b/routers/api/v1/admin/user.go
index c32a98d0c5..bccde18df6 100644
--- a/routers/api/v1/admin/user.go
+++ b/routers/api/v1/admin/user.go
@@ -97,14 +97,12 @@ func CreateUser(ctx *context.APIContext) {
 
 	if u.LoginType == auth.Plain {
 		if len(form.Password) < setting.MinPasswordLength {
-			err := errors.New("PasswordIsRequired")
-			ctx.APIError(http.StatusBadRequest, err.Error())
+			ctx.APIError(http.StatusBadRequest, "PasswordIsRequired")
 			return
 		}
 
 		if !password.IsComplexEnough(form.Password) {
-			err := errors.New("PasswordComplexity")
-			ctx.APIError(http.StatusBadRequest, err.Error())
+			ctx.APIError(http.StatusBadRequest, "PasswordComplexity")
 			return
 		}
 
diff --git a/routers/api/v1/org/action.go b/routers/api/v1/org/action.go
index fb1277a5f4..3f1135dcf3 100644
--- a/routers/api/v1/org/action.go
+++ b/routers/api/v1/org/action.go
@@ -387,7 +387,7 @@ func (Action) CreateVariable(ctx *context.APIContext) {
 		return
 	}
 	if v != nil && v.ID > 0 {
-		ctx.APIError(http.StatusConflict, util.NewAlreadyExistErrorf("variable name %s already exists", variableName).Error())
+		ctx.APIError(http.StatusConflict, "variable name already exists")
 		return
 	}
 
diff --git a/routers/api/v1/repo/action.go b/routers/api/v1/repo/action.go
index cfb9f8bf5f..5fc2e97d7a 100644
--- a/routers/api/v1/repo/action.go
+++ b/routers/api/v1/repo/action.go
@@ -361,7 +361,7 @@ func (Action) CreateVariable(ctx *context.APIContext) {
 		return
 	}
 	if v != nil && v.ID > 0 {
-		ctx.APIError(http.StatusConflict, util.NewAlreadyExistErrorf("variable name %s already exists", variableName).Error())
+		ctx.APIError(http.StatusConflict, "variable name already exists")
 		return
 	}
 
@@ -1062,7 +1062,7 @@ func ActionsDispatchWorkflow(ctx *context.APIContext) {
 	workflowID := ctx.PathParam("workflow_id")
 	opt := web.GetForm(ctx).(*api.CreateActionWorkflowDispatch)
 	if opt.Ref == "" {
-		ctx.APIError(http.StatusUnprocessableEntity, util.NewInvalidArgumentErrorf("ref is required parameter").Error())
+		ctx.APIError(http.StatusUnprocessableEntity, "ref is required parameter")
 		return
 	}
 
@@ -1560,7 +1560,7 @@ func ListWorkflowRunJobs(ctx *context.APIContext) {
 
 	// Avoid the list all jobs functionality for this api route to be used with a runID == 0.
 	if runID <= 0 {
-		ctx.APIError(http.StatusBadRequest, util.NewInvalidArgumentErrorf("runID must be a positive integer").Error())
+		ctx.APIError(http.StatusBadRequest, "runID must be a positive integer")
 		return
 	}
 
diff --git a/routers/api/v1/repo/mirror.go b/routers/api/v1/repo/mirror.go
index 6f72c9613c..c76946493a 100644
--- a/routers/api/v1/repo/mirror.go
+++ b/routers/api/v1/repo/mirror.go
@@ -5,6 +5,7 @@ package repo
 
 import (
 	"errors"
+	"fmt"
 	"net/http"
 	"strings"
 	"time"
@@ -344,8 +345,12 @@ func CreatePushMirror(ctx *context.APIContext, mirrorOption *api.CreatePushMirro
 	repo := ctx.Repo.Repository
 
 	interval, err := time.ParseDuration(mirrorOption.Interval)
-	if err != nil || (interval != 0 && interval < setting.Mirror.MinInterval) {
-		ctx.APIError(http.StatusBadRequest, err.Error())
+	if err != nil {
+		ctx.APIError(http.StatusBadRequest, fmt.Sprintf("invalid interval: %v", err))
+		return
+	}
+	if interval != 0 && interval < setting.Mirror.MinInterval {
+		ctx.APIError(http.StatusBadRequest, fmt.Sprintf("interval is shorter than minimum %v", setting.Mirror.MinInterval.String()))
 		return
 	}
 
diff --git a/routers/api/v1/repo/release.go b/routers/api/v1/repo/release.go
index d199a77ba5..a4fc03ae32 100644
--- a/routers/api/v1/repo/release.go
+++ b/routers/api/v1/repo/release.go
@@ -4,7 +4,6 @@
 package repo
 
 import (
-	"fmt"
 	"net/http"
 
 	auth_model "gitea.dev/models/auth"
@@ -276,7 +275,7 @@ func CreateRelease(ctx *context.APIContext) {
 			} else if release_service.IsErrProtectedTagName(err) {
 				ctx.APIError(http.StatusUnprocessableEntity, err.Error())
 			} else if git.IsErrNotExist(err) {
-				ctx.APIError(http.StatusNotFound, fmt.Sprintf("target \"%v\" not found: %v", rel.Target, err))
+				ctx.APIError(http.StatusNotFound, "target not found")
 			} else {
 				ctx.APIErrorInternal(err)
 			}
diff --git a/routers/api/v1/user/action.go b/routers/api/v1/user/action.go
index 08abe85ac8..1086b22192 100644
--- a/routers/api/v1/user/action.go
+++ b/routers/api/v1/user/action.go
@@ -148,7 +148,7 @@ func CreateVariable(ctx *context.APIContext) {
 		return
 	}
 	if v != nil && v.ID > 0 {
-		ctx.APIError(http.StatusConflict, util.NewAlreadyExistErrorf("variable name %s already exists", variableName).Error())
+		ctx.APIError(http.StatusConflict, "variable name already exists")
 		return
 	}