In haste, right after updating to the new software, I had imported albums from Tidal. Later, I decided I wanted to get rid of them. There were quite a few of them and after deleting many of them I noticed that the core became unresponsive so I had to reboot. This happened several times.

MD600(2x2TB); iPad Pro
LR. 818v3, 8000SE
HT. 861v8+ID41,HD621; BW 2x802D,HTM1D,4x804S;SVS sub; Mac 5 MC501s; RGP 600Pro, JVC X950; Radiance Pro; Oppo 203
FR. G65, DSP3200-3300 DSW, HD621; Mac MC152; Oppo 103, PDP TCP65VT60, Radiance 2124; RGP1200C
4. G65, DSP3200-3300,HD621; OPPO 83, Radiance XE PDP
5. 818v3; Prime HP Amp; HD800