Almost all setup and happy with my mobile emClient now but need help with one last issue… I am unable to sync my Google Calendar default folder (other folders work from the same account) with the following error:
[Google Calendar] Synchronizing folder ‘GMail/Calendar’ failed due to the following error: Format_InvalidStringWithValue, −1
Can someone explain why and how to fix?
/Niklas
Also, syncing the Google default Calendar works on the desktop app.
//Niklas
Got some assistance from ChatGPT 
Have now emptied my entire calendar to see if I could identify the issue. Also, what may not be clear in the text below is:
Hello,
I’m experiencing a persistent issue with the Android version of eM Client when attempting to sync my Google Calendar. The synchronization fails with the following error:
Format_InvalidStringWithValue, −1
This occurs specifically in the Android app – synchronization works perfectly on my Windows computer and also on iPhone, both using the same Google account.
I’ve already tried the following without success:
• Emptied my entire Google Calendar
• Removed and re-added the Google account in the app
• Cleared all app data and cache on Android
• Restarted the phone and reinstalled the app
Despite having no calendar data left, the sync fails immediately upon attempting to activate or view the calendar. The error log mentions LoadWeekDayNumArray, suggesting the app is trying to parse an invalid or missing weekday value.
This appears to be a bug in how the Android app handles calendar entries (perhaps recurring events or deleted items), even when nothing remains in the calendar.
Could you please investigate this or advise on any known issue or workaround?
I’m experiencing a persistent issue with the Android version of eM Client when attempting to sync my Google Calendar. The synchronization fails with the following error:
Format_InvalidStringWithValue, −1
I’ve already tried the following without success:
• Emptied my entire Google Calendar
• Removed and re-added the Google account in the app
• Cleared all app data and cache on Android
• Restarted the phone and reinstalled the app
Check if you are using the latest Droid Beta version 10.3.1746 via the Playstore.
If you already have the latest Android app, then try “repairing your Google calendar”. Go to the Calendar section of the Android app. Then “press and hold your finger” on the word “Calendar under your Gmail account, and then “press Properties” at the bottom. Then “press Repair” which will then re-sync your online calendar to eM Client. Then see if the calendar works.
If the repair still doesn’t make any difference, then suggest to close eM Client and clear the app “data” again. Then using eM Client for desktop go to “Menu / Tools / QR Export” (Pc) or “Tools / QR Export” (Mac), to export the desktop settings etc to your Android mobile. When you open the Android app, you press “Migrate from desktop” and scan the QR code that appears in eM Client on the desktop. Then see if the calendar works.
Lastly if clearing the app data and exporting the desktop settings via QR Code to the Android app still has the same problem, then suggest next to email [email protected] .
And I now have this both on Android and Desktop.
Then as your desktop and mobile app are doing the same thing, then sounds like possibly your Google account calendar online has a problem.
Advise if you have a current active paid Pro or Personal version, go to the VIP support page and login and lodge a support ticket.
