Unfortunately, we do not plan to add a web browser support for Remote Utilities in the nearest future. Remote Utilities is a standalone software and in cases when the installation in not possible, you can easily run our no-install portable modules instead, such as Agent and Portable Viewer. The no-install modules can be stored on a usb-drive or other portable storage device and can be downloaded from our website here. However, it's still possible that in the future we might add the web browser support as well. Unfortunately, there's no specific ETA on this yet. Sorry if this makes our software less useful for you.
I've checked on this request with our developers and even though unfortunately we do not have the freeBSD support planned in the nearest plans, we will do our best to add it in the future. An approximate timeline for the freeBSD support might be after the final stable releases of Viewer and Host for Mac/Linux are available, but unfortunately we cannot provide any specific ETA on this yet.
Perhaps, the issue might be caused by the Host settings or some other file in the installation folder being somehow damaged by some antivirus/firewall software activity. You can try completely uninstalling the Host completely along with cleaning up all the remaining traces of the program as described in this guide. After uninstalling Host please restart the remote machine and then try installing Host once again. This time after installing Host please also make sure to add its installation folder C:\Program Files (x86)\Remote Utilities - Host\* to the antivirus/firewall software exception list if you have any installed. Here's a guide on this that might be helpful.
Unfortunately, the File Transfer connection mode is not supported in mobile Viewer yet. As of this writing only Viewer for Windows supports the File Transfer mode and as for Viewer for Mac/Linux and mobile Viewer as well - the File Transfer mode is definitely is in our roadmap and we will implement it in the future updates. Sorry if this makes our software less useful for you.
We believe that the issue was definitely caused by something on the ISP's side (most likely they were temporarily blocking access to our servers by mistake) since we've had other users who had reported similar issues with the same ISP as well. A couple of those users reported about the issue to the TPG/iiNet and they've restored the access to our servers. You can learn more about the issue in this Community thread.
Please feel free to let us know if you have more questions.