When the String "context=" (with any value after the "=") exists in the description of an appointment, the appointment can't be save without any error message in the user interface.
In the logfile the following errors are written:

2026-05-22T10:06:50+02:00 x-mc03 5d940782490e[671]: May 22 10:06:50 5d940782490e sogod [110791]: [ERROR] <0x0x563c72601e50[GSUInlineString]> json parser: Expected value while parsing array, attempting once more after unescaping...
2026-05-22T10:06:50+02:00 x-mc03 5d940782490e[671]: May 22 10:06:50 5d940782490e sogod [110791]: [ERROR] <0x0x563c72601e50[GSUInlineString]> total failure. Original string is: {"categories":[],"alarm":{},"delta":0,"endDate":"2026-05-22","isErasable":1,"id":"1D26B-6A100E80-3-107F3AE0.ics","attachUrls":[{"value":""}],"pid":"personal","isTransparent":0,"userHasRSVP":0,"calendar":"Clemens Work","localizedEndDate":"Friday, May 22, 2026","summary":"test","comment":"con***="" May 22, 2026","type":"appointment","start":"2026-05-21T22:00:00.000Z","end":"2026-05-21T22:00:00.000Z","$hasAlarm":false,"destinationCalendar":"personal","selected":false,"delegatedTo":"","startTime":"00:00","endTime":"00:00","dueDate":"","dueTime":"","completedDate":""}
2026-05-22T10:06:50+02:00 x-mc03 5d940782490e[671]: May 22 10:06:50 5d940782490e sogod [110791]: [ERROR] <0x0x7fbea6fac860[NSConstantString]> json parser: Expected value while parsing array, attempting once more after unescaping...
2026-05-22T10:06:50+02:00 x-mc03 5d940782490e[671]: May 22 10:06:50 5d940782490e sogod [110791]: [ERROR] <0x0x7fbea6fac860[NSConstantString]> total failure. Original string is: Can't parse JSON string