Modern antivirus programs (and Windows Defender) are often aggressive toward emulators. They may flag the "save" action as a suspicious process trying to modify files on your hard drive.
"there was an unhandled exception trying to save your ROM to disk" is a common crash in the Universal Pokemon Randomizer (UPR) Modern antivirus programs (and Windows Defender) are often
This provides the most detailed diagnostic output, which can be invaluable for identifying the exact problem. This is a common recommendation on the software's GitHub page. This is a common recommendation on the software's
Sometimes the source file itself is the issue. If you are using a ROM randomizer and the source file is damaged (often due to an incorrectly applied patch), the software crashes when it reaches the corrupt section during the save process. Missing or incompatible BIOS files can also cause crashes. Missing or incompatible BIOS files can also cause crashes
Ensure there is at least 100MB of free space.
Modern anti-virus software, particularly the "Controlled Folder Access" feature in Windows Defender, treats emulators as unknown applications. It may block the emulator from saving data, triggering an unhandled exception.