I can't install Catia, I have followed all the steps, I go to the apps, choose a Catia app (eg part design), click on it, it says 'Part Design Is Not Installed'. I then click on 'Install Now'. A popup appears showing this:

I then click Install All Granted Roles (clicking 'install all roles containing part design' also fails), it loads for a few seconds, and then a popup appears saying 'Launching installation' and a few seconds later it says 'Installation Error':

I have read elsewhere that it is the Microsoft visual c++ redistributable that is the issue, and I have tried every single combination of 2015, 2017, and more recent versions, including neither installed. I have tried reinstalling the 3DEXPERIENCE launcher, still does not fix the problem. Please help!

When using Inspect Element, I found the point at which it fails:

it is the 'Function' that attempts to load for a few seconds, and then returns "Fail to download Media!"

This is the error selected:

When opening the request url (https://dslauncher.3ds.com:20300/function), I get this:

{"returnCode": 105, "commentary": "Invalid HTTP verb ! ( POST required instead of : GET )", "content": null}

And in inspect element, the Response is this:
{"returnCode": 154, "commentary": "Fail to download Media!", "content": {"functionName": "installMedia", "params": {"clusterID": "academia", "processToInstallForOid": [{"oiid": "R1132100892906", "process": ["E95", "ENO3DXN_RP", "VCS", "ENONCHA_RP", "UYE"]}, {"oiid": "R1132100892905", "process": ["ENOIXPV_RP", "ENOBCDF_RP", "CHG_RP", "SPI_RP"]}], "osds": "win_b64", "release": "R421", "webServiceURL": "https://software.3ds.com/webservices/jsonrpc/", "codeType": "DESKTOP_Cloud", "levelType": "Both", "codeLevel": "20190927T150324Z", "instVarData": {"MyAppsURL": "https://eu1-academia-apps.3dexperience.3ds.com:443/enovia/resources/AppsMngt", "Cas": "TGT-2439804-3zdk2X7R9vjKys0RibETtcUhH3lN5e3iHXGV6kbUaM66hMOraW-cas", "PassportUrl": "https://eu1-ds-iam.3dexperience.3ds.com", "x3ds_transient_auth_url": "https://eu1-ds-iam.3dexperience.3ds.com/3DPassport/api/login/cas/transient?tgt=TGT-2438300-bruS0Lw2wHcmGhBFkry929KL1HQ42biXRn14saFuRbYeTXTVLv-cas"}, "dataStoragePath": null, "baseInstallIdForHF": null}}}

And this is what was on the console:

I hope that helps, please let me know if you require any more diagnostic information