Why it appears: On rare occasions, such as the application from which you're trying to copy quits unexpectedly, then you return to Photoshop.
How to fix it: Really not much you can do about this one; it's just one of those error messages that doesn't have a “fix.”
Why it appears: You enter a value into a field in a dialog (such as a filter dialog), and the number exceeds the maximum value allowed.
How to fix it: Click OK and enter a lower value. Note: If you're not sure what maximum value can be entered into a field, guess an extremely high number, and Photoshop will “tell” you what the numerical range for that field is.
Why it appears: The document you're opening does not have an embedded color profile.
How to fix it: It's not really a fix, but a choice: leave the document as is, not assigning any color profile; assign your current working profile; or select a profile from the options provided.
Why it appears: The document you're opening has an embedded color profile that does not match your working color profile.
How to fix it: It's not really a fix, but a choice: leave the document as is, using the embedded color profile instead of the working profile; convert the document to your current working profile; or discard the existing profile, using none at all.
Why it appears: You're pasting from a document that has an embedded color profile that does not match your working profile.
How to fix it: You have two choices: convert the pasted content to your working color profile or leave it as is.
Why it appears: Choose any of the options under Edit>Purge and you'll get this warning (reminder?).
How to fix it: You can't avoid this warning; it's one of those “are-you-sure-you-want-to?” messages. You either click OK to continue purging or Cancel if you decide not to purge.
Why it appears: You attempt to choose a file from the File>Open Recent submenu, but the document must have been moved, deleted, or renamed.
How to fix it: Go to your desktop and press Command-F (PC: Windows-F) to perform a manual search on your hard disk for the document that the Open Recent submenu doesn't “remember.”
Why it appears: You have previously customized the menus (Edit>Menus), and now are choosing a workspace that uses different menus (Window>Workspace).
How to fix it: You must decide whether you want to save your previous custom menus (Save), not save the menus and continue (Don't Save), or Cancel to stick with your custom menus.
Why it appears: You're under General Preferences (Command-K [PC: Control-K]), and you've clicked on the Reset All Warning Dialogs button.
How to fix it: This is more of a confirmation than a warning, telling you that any dialogs that have been disabled by clicking the Don't Show Again checkbox will now be shown.
Why it appears: You have chosen either a built-in workspace or a workspace that you have saved (from the Window>Workspace submenu), and that workspace will change the existing menus or keyboard shortcuts.
How to fix it: If you don't want to change the modified menus or shortcuts, click No to stop from switching to that workspace. Click Yes to accept the change, including the new menus and shortcuts.