I can now confirm that after downgrading from v.4.0 to v.3.4 for both Engine OS and Engine Desktop and rebuilding the library from scratch, all problems have been resolved. There are no more crashes, the library remains intact and retains approximately its original size even after use in my Prime 2 and the access times when searching in the MicroSD card are acceptable.
On the one hand, my comparison refers to a library that was newly set up under Engine 3.4 in April 2024, which came into contact with Engine 4.0 for the first time this week and has not worked on MicroSD cards in at least three independent attempts since then. On the other hand, the comparison refers to a library rebuilt from scratch yesterday with exactly the same tracks under the same conditions, just without any contact to Engine 4.0.
PC is a HP EliteDesk with Ryzen 5, 32GB RAM, Win 11. System, engine desktop, tracks & library are located on an internal WD 2TB M.2 NVMe SSD. No Serato, no external stuff, no bells & whistles. Just a straight forward workflow with well maintained tags in well maintained folders that are imported to Engine Desktop’s library and shall be transferred together to a MicroSD-Card for use on a Prime 2.
As far as I can tell from this experience, only the update to version 4.0 is causing the problems with the library, as I made the comparison ceteris paribus. Whether this is a general problem with version 4.0, whether it only becomes visible with my files (here: FLAC/MP3 mixed), only with certain file sizes (here: 32k files, 600 GB hard disc space), I cannot judge. I also can’t say if downgrading Engine OS and Engine Desktop is enough to fix the problem without rebuilding the library from scratch, because I haven’t tried that
Yes, the MicroSD card is still very slow. I will therefore soon be replacing it with an internal S-ATA SSD drive in my Prime 2. However, as a precaution, I will make backups of the original library, both from the PC and from the external data carrier, before updating to a new version of Engine OS or Engine Desktop.
Ed.: The new 1TB SSD has just arrived, nothing fancy. I simply copied the entire MicroSD card and used the same volume name so that synchronisation is not affected. Works perfectly and much faster than the external “fast” MicroSD card.