Hi @ArvinIG,
thank you for your reply, yes in fact I have already tried a lot to debug it and it does not seem to be Firefox itself causing the problem. A portable installation of Firefox is something that you can put on a USB stick and move it from PC to PC. So the exactly same installation on the USB stick works on two PCs and fails on the thir with the error above. Also a non-portable fresh installation of Firefox shows the same behavior as does the Tor Browser (Firefox based).
Chrome however works, but Chrome uses a completely different rendering engine.
I really would like to understand the root cause of this issue as it may indicate other (hidden) issues on the computer which fails to load the platform. Please also note the posts above, it seems to affect others as well.
However I have found a way to reproduce the problem even on machines where it would usually work with Firefox:
1. Open Firefox and clear all history with all site data, cookies and cache (select timeframe "Everything" and click all checkboxes)
2. Load the MyIG Dashboard
3. Press F12 to open the Debugger
4. In the Debugger, switch to the Network Tab
5. On the right side of the debugger set Throttling to "Regular 2G"
6. Click the "Open Platform" button and wait until the error shows
Now repeat the same steps but this time choose "Good 2G" instead. This time the platform will load successfully.
The explanation for this behavior seems to be related to the JavaScript engine and the related timings there. Very fast computers might have issues with Firefox JavaScript timings resulting in the error behaviour. So this could indicate that CPU speed and hyperthreading might show this behaviour on some computers while others won't suffer from it.
I'm not sure if 1st level support at the UK helpdesk is able to understand this problem as it is very technical and related to platform programming. Maybe you or somone else could advise to whom it could be addressed for solution.
Many thanks in advance.