I remember a friend in graduate school throwing an early edition of Jurgen Neukirch's Algebraic Number Theory book against a wall (so hard that it split the binding) after he had worked for a number of days to reconcile something he realized was an error (or typo) in the book.

For the life of me, I cannot remember what this error was.

Has anyone come across a particularly annoying error in an early edition of Neukirch? If so, what was it?

To give context to some of the answers below, I include the original statement of this question, which Scott and David pointed out was a bit too "spammy". Sometimes I feel like a little kid at a sleepover when I am reading MO, and post a bit wildly... so I'm grateful for the voices of reason:

What are your "favorite" annoying errors and typos in otherwise excellent sources?

Please especially try to include subtle errors that can mislead, as these are very important.

Disclaimer: The author of this quesion thinks that working to resolve an error like this is a very worthwhile exercise, at least from the standpoint of having cool war stories that make a topic memorable. I'm not sure, therefore, whether I would want to post an answer to this question myself. I posted the question because I thought it would be fun.

I remember a friend in graduate school throwing an early edition of Jurgen Neukirch's Algebraic Number Theory book against a wall (so hard that it split the binding) after he had worked for a number of days to reconcile something he realized was an error (or typo) in the book.

For the life of me, I cannot remember what this error was.

Has anyone come across a particularly annoying error in an early edition of Neukirch? If so, what was it?

To give context to some of the answers below, I include the original statement of this question:

What are your "favorite" annoying errors and typos in otherwise excellent sources?

Please especially try to include subtle errors that can mislead, as these are very important.

Disclaimer: The author of this quesion thinks that working to resolve an error like this is a very worthwhile exercise, at least from the standpoint of having cool war stories that make a topic memorable. I'm not sure, therefore, whether I would want to post an answer to this question myself. I posted the question because I thought it would be fun.

I remember a friend in graduate school throwing an early edition of Jurgen Neukirch's Algebraic Number Theory book against a wall (so hard that it split the binding) after he had worked for a number of days to reconcile something he realized was an error (or typo) in the book.

For the life of me, I cannot remember what this error was.

Has anyone come across a particularly annoying error in an early edition of Neukirch? If so, what was it?

To give context to some of the answers below, I include the original statement of this question, which Scott pointed out was a bit too "spammy". Sometimes I feel like a little kid at a sleepover when I am reading MO, so I'm grateful for the voices of reason:

What are your "favorite" annoying errors and typos in otherwise excellent sources?

Please especially try to include subtle errors that can mislead, as these are very important.

Disclaimer: The author of this quesion thinks that working to resolve an error like this is a very worthwhile exercise, at least from the standpoint of having cool war stories that make a topic memorable. I'm not sure, therefore, whether I would want to post an answer to this question myself. I posted the question because I thought it would be fun.

I remember a friend in graduate school throwing an early edition of Jurgen Neukirch's Algebraic Number Theory book against a wall (so hard that it split the binding) after he had worked for a number of days to reconcile something he realized was an error (or typo) in the book.

For the life of me, I cannot remember what this error was.

Has anyone come across a particularly annoying error in an early edition of Neukirch? If so, what was it?

To give context to some of the answers below, I include the original statement of this question, which Scott and David pointed out was a bit too "spammy". Sometimes I feel like a little kid at a sleepover when I am reading MO, and post a bit wildly... so I'm grateful for the voices of reason:

What are your "favorite" annoying errors and typos in otherwise excellent sources?

Please especially try to include subtle errors that can mislead, as these are very important.

Disclaimer: The author of this quesion thinks that working to resolve an error like this is a very worthwhile exercise, at least from the standpoint of having cool war stories that make a topic memorable. I'm not sure, therefore, whether I would want to post an answer to this question myself. I posted the question because I thought it would be fun.

This is meant as a public service.

Sometimes wonderful sources contain errors that can stump a novice for a long time. I remember a friend in graduate school throwing an early edition of Jurgen Neukirch's Algebraic Number Theory book against a wall (so hard that it split the binding) after he had worked for a number of days to reconcile something he realized was an error (or typo) in the book.

What are your "favorite" annoying errors and typos in otherwise excellent sources?

Please especially try to include subtle errors that can mislead, as these are very important.

Disclaimer: The author of this quesion thinks that working to resolve an error like this is a very worthwhile exercise, at least from the standpoint of having cool war stories that make a topic memorable. I'm not sure, therefore, whether I would want to post an answer to this question myself. I posted the question because I thought it would be fun.

I remember a friend in graduate school throwing an early edition of Jurgen Neukirch's Algebraic Number Theory book against a wall (so hard that it split the binding) after he had worked for a number of days to reconcile something he realized was an error (or typo) in the book.

For the life of me, I cannot remember what this error was.

Has anyone come across a particularly annoying error in an early edition of Neukirch? If so, what was it?

To give context to some of the answers below, I include the original statement of this question, which Scott pointed out was a bit too "spammy". Sometimes I feel like a little kid at a sleepover when I am reading MO, so I'm grateful for the voices of reason:

What are your "favorite" annoying errors and typos in otherwise excellent sources?

Please especially try to include subtle errors that can mislead, as these are very important.

Disclaimer: The author of this quesion thinks that working to resolve an error like this is a very worthwhile exercise, at least from the standpoint of having cool war stories that make a topic memorable. I'm not sure, therefore, whether I would want to post an answer to this question myself. I posted the question because I thought it would be fun.