use tempImportFile

app/app-detail.component.ts

@@ -216,10 +216,16 @@ export class AppDetailComponent implements OnInit, OnChanges {
         let ext = path.extname(this.import_path);
         if (ext === '.zst') {
             try {
+                targetApp.status.status = 'installing';
+                if(this.import_path.includes(' ') && this.import_path.match(/[^\x00-\x7F]/)) {
+                    console.log('import file name contains non-ascii, coping to temp file');
+                    let tempImportFile = path.join(option.installLibrary, 'downloading', 'import.zst');
+                    await this.appsService.copyFile(this.import_path, tempImportFile);
+                    this.import_path = tempImportFile;
+                }
                 console.log('extracting import file');
                 await this.appsService.createDirectory(option.installDir);
                 await new Promise((resolve, reject) => {
-                    targetApp.status.status = 'installing';
                     this.appsService.extract(this.import_path, option.installDir).subscribe(
                         (lastItem: string) => {
                             targetApp.status.progressMessage = lastItem;