I am having a problem that bothers me now for six days. I did not find a solution anywhere and have absolutely no idea what is going on with my work.
I am working with Kile and have a project with several chapters. If I insert an additional line in a certain chapter the txt-file cannot be compiled and I get error messages about missing or bad math delimiters. When I use % in front of that line and insert another line the same error messages appear. This happens with every additional line I insert. No matter if it contains only text or equations in \( \) or \[ \] or align environment.
Since the error messages are always referring to the chapter I did put everything together into one file. I cannot find any missing delimiters and however the error messages do not appear, when I process the subdocument only.
I would be really thankful to anybody who has an idea about what it could be that I did wrong... It is not about fonts. I replaced all ä with ae and all ß with \ss. I am using the package amsmath and therefore the use of \( and \[ instead of $ or $$ is valid, also the use of align instead of eqnarray.
Thanks for every advice

I would post an example but I don't have any idea what I could post here except the output or the error messages and I don't know if this is of any help.
Gedankenpause