Spotify deleting all offline files and redownloading them

[SmokeyD]

Hi All,

I have spotify running on my (Linux) Desktop. I am using a prepaid (pay per MB or hour) internet connection and thus don't have the luxury of being online all the time. So I downloaded quite a few playlists for offline listening. My Desktop unfortunately just told me offline access has been revoked. I read the thread on why that can happen and how I can re-enable offline availability, but for some reason, spotify deletes all offline files first, and then starts re-downloading them. THis is pretty annoyinng on my internet connection. I have, fortunately, a backup of all offline storge of spotify (form the Storage folder), and copied the backup back to the Storage folder. This used to work fine, and instead of redownloading files, spotify would just mark the songs as being available again. Now though, as soon as I start spotify, it deletes all these files again, and starts re-downloading them. 

Is there any way to resolve this so spotify uses the files that I already downloaded instead of redownloading them? If not, it will take me multiple days and a lot of money in internet connection to re-download all files again, and this being the umpteenth time this happend (normally only on my android devices, lately with the change from spotify to the spotify-music app), it kind of makes me exasperated with spotify and is making me consider saving the €10 per month I am paying now, and falling back on illegal downloads as I am on the move a lot, and travelling to many different countries with bad internet connections. It will be both cheaper, and more reliable.

[Joe]

There's no way to back up and restore the spotify cache, as far as I know. Do you have offline music on any other devices? Take a look at your offline devices page to see if you recognose all the devices and maybe delete them all and start over.

[SmokeyD]

It is definitely possible to backup your cache. Just copy the whole Storage folder and everything in it (I actually copied the parent folder). It did that multiple times as a backup and it works. Of course it only works with the same spotify account you can't copy music between accounts, and maybe not even between devices (I never tried). But what is important I think is the index.dat file in the Storage folder. When that is corrupted or not present, your whole cache is useless it seems. I tried syncing a few files, stopping spotify, removing the index.dat, and starting spotify again. That triggered spotify emptying the whole cache folder and starting all over with downloading (and trigered the message again that offline access was revoked). So I think that is what happend with me in the first place. The index.dat got corrupted or whatever. I don't think there is a way to restore it, and it is also unreadable. It is a binary file and I have no clue as to the file type. 

[tsterkel]

Does anyone KNOW the answer? I see some good guesses by no answers

[MetalGodwin]

Same here, from Ubuntu 16.04.

I use my main work laptop with offline lists. I don't know how Spotify recognize the device as the same offline enabled device, of the three allowed with premium account. But this laptop is online using wireless or cable @home, internet sharing from phone or wireless / cable at several work locations. It seems it's taking up atleast two of the three available spots of allowed offline devices too.

I need to test more, but I think that if i remove offline list, reinstall Spotify and add offline list the list stay download for a while. (presumeable till I change network, but ais I need to test more) 

Anything similar in your situations?