Spotify : Problem after 1 year use with 3e party plugin

I'm using Sotify Premium on my Synology NAS for more than 12 mounths now. I have used it with the standard Thriode 3e party plugin. After a Perl upgrade it is not working any more. For details of my set-up see below. The listing is working with spotify but whenever album-art must be loaded it gives an error "general transient error". This means that nothing is showing and nothing can be selected.

Any Ideas ?

Copy from log where error is present:

[21:41:07.539148] toplist_callback:1013 toplist artists: 100
[21:41:09.007860] metadata_updated:86 new meta
[21:41:09.354419] main:619 req: browse.json res: spotify:artist:5eir5zFJpES4j7gsymbVyl par: (null) prot: HTTP/1.0 auth: (null)
[21:41:09.354687] main:1026 created artist browse
[21:41:20.828662] log_message:81 log: 19:41:20.828 E [ap:4172] ChannelError(0, 1, metadata)
[21:41:22.398314] log_message:81 log: 19:41:22.398 E [ap:4172] ChannelError(1, 1, browse-artist)
[21:41:22.398783] browse_artist_callback:166 browse artist: General transient error
[21:41:29.293422] metadata_updated:86 new meta
[21:41:41.333050] log_message:81 log: 19:41:41.333 E [ap:4172] ChannelError(1, 1, metadata)
[21:41:44.059636] log_message:81 log: 19:41:44.059 E [ap:4172] ChannelError(0, 1, metadata)

System setup:

Synology DS212+ with DSM 5.2-5565 Update 2
Perl software on NAS 5.18.4-0022
LMS 7.7.3-042 with Triode v2.3.9
Duet Receiver Firmware 77
IPad 2 with Squeezepad app version 1.11.0

Again thanks for your support

Jos Damen
The Netherlands