SuperMap
diff --git a/‎src/openlayers/overlay/vectortile/MapboxStyles.js
+1-1 b/‎src/openlayers/overlay/vectortile/MapboxStyles.js
+1-1
@@ -388,7 +388,7 @@ export class MapboxStyles extends Observable {
               })
           }
           if (fieldName === 'sprite' || fieldName === 'glyphs' || fieldName === 'url') {
-              if (typeof styles[fieldName] === 'string' && !CommonUtil.isAbsoluteURL(styles[fieldName])) {
+              if (styles[fieldName] && typeof styles[fieldName] === 'string' && !CommonUtil.isAbsoluteURL(styles[fieldName])) {
                   styles[fieldName] = CommonUtil.relative2absolute(styles[fieldName], baseUrl);
               }
           }
Original file line number	Diff line number	Diff line change
`@@ -388,7 +388,7 @@ export class MapboxStyles extends Observable {`
`388`	`388`	`})`
`389`	`389`	`}`
`390`	`390`	`if (fieldName === 'sprite' \|\| fieldName === 'glyphs' \|\| fieldName === 'url') {`
`391`		`- if (typeof styles[fieldName] === 'string' && !CommonUtil.isAbsoluteURL(styles[fieldName])) {`
	`391`	`+ if (styles[fieldName] && typeof styles[fieldName] === 'string' && !CommonUtil.isAbsoluteURL(styles[fieldName])) {`
`392`	`392`	`styles[fieldName] = CommonUtil.relative2absolute(styles[fieldName], baseUrl);`
`393`	`393`	`}`
`394`	`394`	`}`