If your Outlook profile isn’t working, you can still access your OST data by converting it to PST. OST files are tied to your Outlook account, so when the profile is encrypted or inaccessible, the mailbox becomes unreachable. In such cases, using a reliable OST to PST conversion tool, like Stellar Converter for OST, can help. The software allows you to safely extract emails, contacts, calendars, and attachments directly from the OST file without relying on Outlook. You can scan the OST, preview mailbox items, and export the data to a PST file, which can then be imported into Outlook or Office 365. This approach ensures that all your mailbox data is preserved and accessible, even if the original Outlook profile is not working.

I’ve faced the same issue; manually converting multiple ICS files is messy and risks losing recurring events or details. From my experience, SysTools ICS Converter is a solid choice for bulk conversion.

Why does it work well?

List item supports batch processing, add multiple ICS files or an entire folder at once.
Converts to PST, CSV, iCal/ICS, and other formats.
Preserves event details, including descriptions, attendees, and recurring events.
Can handle large ICS batches without errors.

Tips:
Always back up your original ICS files before conversion.
After conversion, spot-check a few events to ensure recurring events and reminders are intact.
If using CSV, check that all columns (start/end, description, attendees, etc.) are correct.
Overall, it’s a reliable way to quickly convert multiple ICS files without data loss, saving a ton of time compared to manual methods.

You can split a large ICS file by exporting each event into its own ICS, and the easiest way is using SysTools ICS Splitter. It automatically breaks massive ICS files into smaller, event-based or date-based files while preserving all metadata, attachments, and formatting. The tool supports bulk processing, keeps the original folder structure intact, and avoids corruption issues common with manual methods. If you need clean, organized, shareable ICS files without hassle, this utility is a reliable, time-saving option.

Do you want to Import EML to G Suite Account? Then try WholeClear EML to G Suite Converter. It has a simple and user-friendly interface. It imports Bulk EML files at once without data loss. It ensures secure and Batch migration. Provide complete conversion of EML files and attachments. Keep the folder and original structure. Not required additional tools. It supports all Windows OS versions, including 11,10,8, and others. The application provides 24*7 technical help.