I am using pdfMake to generate PDF files. These files are typically 20-50 kb in size. When I try to upload a file, I get this error message:

core.js:6142 ERROR Error: Uncaught (in promise): a: {"name":"NOT_READABLE_ERR","code":4} at resolvePromise (zone-evergreen.js:1213) at zone-evergreen.js:1283 at ZoneDelegate.invokeTask (zone-evergreen.js:406) at Object.onInvokeTask (core.js:28500) at ZoneDelegate.invokeTask (zone-evergreen.js:405) at Zone.runTask (zone-evergreen.js:178) at drainMicroTaskQueue (zone-evergreen.js:582) at ZoneTask.invokeTask [as invoke] (zone-evergreen.js:491) at invokeTask (zone-evergreen.js:1600) at HTMLInputElement.globalZoneAwareCallback (zone-evergreen.js:1626)

With large files (> 200kb) it works fine