Hi Stoiqa,
Does the following help at all?
1. Render the image sequence with ''Automatic saving on render end'' in the Corona preferences. This will save an .CXR file for each frame.
2. Select all the files you want to rename in Windows Explorer. File location will be: (C:\Users\Username\AppData\Roaming\MAXON\Maxon Cinema 4D R22_06E03A84\corona\history)
3. Right-click on one of the selected files and choose "Rename".
4. Delete the existing file extension and type in the new one (in this case, ".exr").
5. Press Enter to apply the new extension to all selected files.
(If the Windows method of renaming files does not work, you could try using a third-party file-renaming tool that can perform batch operations. Here are some popular options:
Bulk Rename Utility (
https://www.bulkrenameutility.co.uk/): This free tool has a simple and user-friendly interface that lets you easily rename files and folders in bulk. You can use it to change file extensions, replace text, add prefixes or suffixes, and more.
Advanced Renamer (
https://www.advancedrenamer.com/): This tool offers a wide range of renaming options, including the ability to change file extensions, remove or replace characters, add dates or times, and more. It supports a variety of file formats and has a preview feature that lets you see the changes before you apply them.
Rename Master (
http://www.joejoesoft.com/vcms/108/): This free tool can rename multiple files and folders at once, using a variety of renaming options. It supports regular expressions, filters, and presets, and has a preview function that shows you how the new names will look.
These tools are all free to use and should be able to help you change the file extensions in bulk.)
Also, does this sound correct to you and can you also tell us where exactly you are getting an error? Is it when importing the file or exporting from AE?