SSL VPN site publishing Angular 5 app encounters "Invalid Character Error"

[beko]

I'm trying to publish a Angular 5 website via SSL VPN portal and I'm getting errors from "sslvpn.js" with all browers.

In the console of firefox for example I'm encountering the following error:

[ul]

DOMException: String contains an invalid character[/ul]

The stacktrace lists a couple of errors like the following in bothw main.js and polyfills.js.

J https://portal.beko-group.com/proxy/53ffeeb3/http/v2_test.intranet.beko-monheim.de/main.818c3e6a30c3... WT6e/</tt</t.prototype.handleError https://portal.beko-group.com/proxy/53ffeeb3/http/v2_test.intranet.beko-monheim.de/main.818c3e6a30c3... WT6e/</$t</t.prototype.bootstrapModuleFactory/</</</< https://portal.beko-group.com/proxy/53ffeeb3/http/v2_test.intranet.beko-monheim.de/main.818c3e6a30c3...

The respective javascript files are UTF-8 encoded and the site itself works fine when accessed directly on the internal LAN. Is there a known issue with SSL VPN rewriting the Angular 5 bundled files?