I need to check something on my own laptop first, but I'll get back to you asap with the simplest workaround I can find to get your MSFS install sorted and simplified on your D: drive, with an easy to access file path like "D:\MSFS Packages" which shouldn't fall foul of issues like exceeding the default maximum path length in Windows.
In the meantime, reading this topic may help give you a bit of an insight. https://www.avsim.com/forums/topic/5836 ... -too-long/
I'm hoping that FS2024 will offer a more user-friendly way for users to move the sim's packages around onto different drives and so on, though I'm not hugely optimistic. I guess time will tell...

Thanks,
Nick