Problem installing updated TopoActive Europe Map 2020.10

Today the updated TopoActive Europe 2020.10 appeared to be installed on my Garmin Fenix 6X Pro and my GPSMAP 66ST. 

However, the installation fails with error message that installation failed - same error on both devices.

I just saw that there are similar issues with Garmin Express for Windows.

The error log contains following information:

2020-05-27 22.02.19 (GMT+02:00) | 59143 | I | [MapUpdate-ActiveEU.2020.10-39817316] Changed to [Downloading] phase.
2020-05-27 22.02.20 (GMT+02:00) | 775 | I | Suppressing notification with message: Das GPSMAP 66ST-Gerät wurde erfolgreich synchronisiert. Zeigen Sie Daten bei Garmin Connect an.
2020-05-27 22.02.20 (GMT+02:00) | 775 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3981731671
2020-05-27 22.02.20 (GMT+02:00) | 775 | I | Successfully sent sync analytics report
2020-05-27 22.06.54 (GMT+02:00) | 59143 | I | [MapUpdate-ActiveEU.2020.10-39817316] The expected files to be built should result in 0 bytes in space.
2020-05-27 22.06.54 (GMT+02:00) | 59143 | I | [MapUpdate-ActiveEU.2020.10-39817316] Changed to [Activating] phase.
2020-05-27 22.06.55 (GMT+02:00) | 64795 | E | ServerRequest failed with Error:Error Domain=HttpStatusCodeErrorDomain Code=500 "(null)" UserInfo={NSErrorFailingURLKey=omt.garmin.com/.../ActivateMapUpdate}
2020-05-27 22.06.55 (GMT+02:00) | 59143 | W | [MapUpdate-ActiveEU.2020.10-39817316] Failed with error: Error Domain=HttpStatusCodeErrorDomain Code=500 "(null)" UserInfo={NSErrorFailingURLKey=omt.garmin.com/.../ActivateMapUpdate}
2020-05-27 22.06.55 (GMT+02:00) | 59143 | I | [MapUpdate-ActiveEU.2020.10-39817316] Changed to [Failed] phase.
2020-05-27 22.06.55 (GMT+02:00) | 59143 | I | [MapUpdate-ActiveEU.2020.10-39817316] Released sleep lock
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3981731671
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3981731671
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3981731671
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | Update Check started for device 3981731671
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | MapUpdateEx Flow: UpdateCheck init 3981731671
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | ConsentService - getConsent:
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | ConsentService - getConsent:
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | ConsentService - getConsent:
2020-05-27 22.06.55 (GMT+02:00) | 775 | I | ConsentService - getConsent:
2020-05-27 22.06.56 (GMT+02:00) | 775 | I | [ReadWifiSettings-3981731671-0A36147] Changed to [Preparing] phase.
2020-05-27 22.06.56 (GMT+02:00) | 775 | I | [ReadWifiSettings-3981731671-0A36147] Preventing computer from sleeping
2020-05-27 22.06.56 (GMT+02:00) | 70915 | I | ReadWifiSettings-3981731671-0A36147 - Reading wifi settings
2020-05-27 22.06.56 (GMT+02:00) | 70915 | I | [ReadWifiSettings-3981731671-0A36147] Changed to [Copying] phase.
2020-05-27 22.06.56 (GMT+02:00) | 70915 | I | ReadWifiSettings-3981731671-0A36147 - Reading wifi settings
2020-05-27 22.06.56 (GMT+02:00) | 70915 | I | Decrypting wifi data for 3981731671
2020-05-27 22.06.56 (GMT+02:00) | 70915 | I | [ReadWifiSettings-3981731671-0A36147] Changed to [Succeeded] phase.
2020-05-27 22.06.56 (GMT+02:00) | 70915 | I | [ReadWifiSettings-3981731671-0A36147] Released sleep lock
2020-05-27 22.06.56 (GMT+02:00) | 775 | E | GetSubscriptionInfoDelegate: Error deserializing JSON object: Error Domain=NSCocoaErrorDomain Code=3840 "No value." UserInfo={NSDebugDescription=No value.}
2020-05-27 22.06.56 (GMT+02:00) | 775 | E | ServerRequest failed with Error:Error Domain=NSCocoaErrorDomain Code=3840 "No value." UserInfo={NSDebugDescription=No value.}
2020-05-27 22.06.57 (GMT+02:00) | 775 | I | MapUpdateEx Flow: MapUpdateEx json factory method
2020-05-27 22.06.57 (GMT+02:00) | 775 | I | MapUpdateEx Flow: MapUpdateEx factory method updated contents for ActiveEU.2020.10
2020-05-27 22.06.58 (GMT+02:00) | 775 | I | MapUpdateEx Flow: UpdateCheck mutableCopy 3981731671
2020-05-27 22.06.58 (GMT+02:00) | 59143 | I | Update Check Complete: [Update Group for device 3981731671 - MU:1, MR:0, MS:0, RM:0, CU:0, RF:0, OF:0, LP:0, SR:35, IQ:0, CQ:0, SF:0, SCU:0, DLCU:0]
2020-05-27 22.06.58 (GMT+02:00) | 59143 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3981731671
2020-05-27 22.06.58 (GMT+02:00) | 5663 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3981731671
2020-05-27 22.06.58 (GMT+02:00) | 5663 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3303477207
2020-05-27 22.06.58 (GMT+02:00) | 5663 | I | MapUpdateEx Flow: UpdateGroup initWithUpdateGroup 3330009826
2020-05-27 22.06.58 (GMT+02:00) | 5663 | I | Cleaned map cache of 0 item(s).

Does anyone have an idea on how to fix this issue?