[Flomet]

Done that - repeatedly. The results are the same

This might be worth a try;
Remove all cards
Update library (this will clean any files from memory)
Reset setting to factory default
Restart the X5
This should start you off the same as when you received it, then just setup to your liking.

Just install one card and test, then the other if all is okay.

I will keep my fingers crossed for you as this problem must be VERY frustrating.

 

[Wokei]

You need to beg, borrow or steal another SD card. It is the only way to know whether it is a bad card or a bad X5. As Wokei pointed out, they can go bad without warning. It's easier if they completely fail - intermittent errors are a real pita
James has given this as a reason why Apple products don't have card slots

My Sandisk 32gb class 10 that died on me ....took out from my phone to transfer some pic to my portable hd and after that re-insert back into my phone ...restart me phone ..just keep on scanning and wont stop ...took out the phone battery.

Re insert back to my laptop and just wont recognized the sd card anymore . Was fuming over it for days trying on my laptop and my family member laptops and phone ..still wont work. Bought a new card ...back in business .

I had 3 sd card going bonker on me ...just me luck.

 

[Cannikin]

This might be worth a try;
Remove all cards
Update library (this will clean any files from memory)
Reset setting to factory default
Restart the X5
This should start you off the same as when you received it, then just setup to your liking.

Just install one card and test, then the other if all is okay.

I will keep my fingers crossed for you as this problem must be VERY frustrating.

 
Just completed this task, and the results were the same. I've selected a different HDtracks album that was shown to "stutter" when the problem was first identified, and it does it as well, after a complete reset as you described above.

 

[Cannikin]

 
You need to beg, borrow or steal another SD card. It is the only way to know whether it is a bad card or a bad X5. As Wokei pointed out, they can go bad without warning. It's easier if they completely fail - intermittent errors are a real pita
James has given this as a reason why Apple products don't have card slots

 
Read below: I did locate another card to test with, and the results were the same: high res albums loaded to the other, newly formatted card behaved the same: they all "stutter" now.

 

[nmatheis]

Cannikin: Have you tried re-flashing firmware 2.0? This would be the "ultimate reset". Kind if like reinstalling OS X or Windows if you've major issues with your computer.

 

[Flomet]

Just completed this task, and the results were the same. I've selected a different HDtracks album that was shown to "stutter" when the problem was first identified, and it does it as well, after a complete reset as you described above.

I'm sorry that did not help you, it was worth a try!

Might be a good idea to contact Joe or James as they know more about the X5 than us frustrated users.

 

[ptravel]

   
I did more tests, reformated the card with the X5 directly, which formats it to FAT32. I copied around 100Gb of flac files, and when i start to build the library it stops around 250 files. In browser mode, all folders are displayed, but i can enter only a small part of it, around the same amount of files (250), other folders are displayed but when i select them it says "no music found". 
I tried with less files (around 40Gb) and have the same issue. Of course the card and its content work perfectly in any other device (PC, card reader on my blu ray player etc). So i don't think 128Gb cards are well supported, maybe it works with a few models but not with mine (Samsung 128Gb card, not a cheap one). 

Sounds like you have a fake card.  Is it a Sandisk?

 

[Cannikin]

I'm sorry that did not help you, it was worth a try!

Might be a good idea to contact Joe or James as they know more about the X5 than us frustrated users.

I'd prefer to have FiiO respond in-thread, since I am not the only person having this problem and I think it warrants a public response.

 

[Flomet]

I'd prefer to have FiiO respond in-thread, since I am not the only person having this problem and I think it warrants a public response.

I am under the impression that Joe and James are FiiO, please correct me if I'm wrong!

 

[Cannikin]

I am under the impression that Joe and James are FiiO, please correct me if I'm wrong!

Sorry, I worded that poorly -- Yes, that is correct. I simply wanted to state that I prefer to have Joe or James respond in this forum, publicly, rather than in private, since I think this deserves to be addressed openly

 

[uzi2]

   
Read below: I did locate another card to test with, and the results were the same: high res albums loaded to the other, newly formatted card behaved the same: they all "stutter" now.

So, it would appear that you have done everything you can to eliminate all other possibilities. The conclusion must be that your X5 has developed a fault and should be returned. I'm sorry none of us could come up with any magic solution.
Sorry if it's already been mentioned, but HDTracks have other files apart from the flacs - have these been transferred to the card? Someone mentioned that a pdf could screw things up.

 

[Flomet]

Sorry, I worded that poorly -- Yes, that is correct. I simply wanted to state that I prefer to have Joe or James respond in this forum, publicly, rather than in private, since I think this deserves to be addressed openly

No problem, and I totally agree with posting in the forum.

 

[Muenchener]

 
Sorry, I worded that poorly -- Yes, that is correct. I simply wanted to state that I prefer to have Joe or James respond in this forum, publicly, rather than in private, since I think this deserves to be addressed openly

This exact type of issues is why I think FiiO should not let people try to solve these problems by themselves. It looks lazy and not caring, even when I'm sure they don't do it on purpose.

AFAIK, this thread is the biggest, most up-to-date data collection on the X5, and it is slowly filling up with problems and malfunctions anecdotes. This is not helping FiiO or X5 sales, and thanks to Google, this thread is the most visible X5-related web site after FiiO's.

Please, Joe or James, try your best to solve this ASAP, and share the solution on this thread, that has become the de facto X5 support site.

 

[tjw321]

...
plugged it into my Mac/card reader
...

Did you remove all the hidden files that the Mac puts on the card before putting it into the X5?

 

[Cannikin]

Did you remove all the hidden files that the Mac puts on the card before putting it into the X5?

You're going to have to be more specific than that. What hidden files?