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The error “The repository CD-ROM does not have a Release file” in Ubuntu typically occurs when the system is trying to access the installation CD-ROM repository that no longer exists or is not valid. This can happen after installation or if the CD-ROM source is no longer available. Here’s how you can fix this issue:
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Repository cdrom Does not Have a Release File
To resolve this problem from terminal you must remove or comment the CD-ROM repository source directly from /etc/apt/sources.list. Use a text editor to modify the sources list. For example, using nano:
sudo nano /etc/apt/sources.list
Add a # at the beginning of this line to comment it out:
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Once done, run the update again, and the error should be gone. This command will now ignore the CD-ROM repository and fetch updates from other sources.
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Not a reader? Watch this related video tutorial: