One of the reasons can be, that you are using an Angular function for the Content field, which breaks if an apostrophe is inserted into this field.
As a solution, you can try updating the Content fields with hexadecimal values for quotes.
The other possible way to fix this (as for a regular text or class field, the apostrophe works fine) would be to check if it is possible to update the template's syntax to use template directives instead of Angular code. For example instead of the original code:
HTML
<div ng-if="'[%% mobile-copy %%]'" class="mobile">[%% mobile-copy %%]</div>\n<div ng-if="!'[%% mobile-copy %%]'" class="mobile">[%% desktop-copy %%]</div>
User this updated one:
HTML
<div class="mobile">[%% mobile-copy %%]</div>\n<div class="desktop">[%% desktop-copy %%]</div>
Alternatively, if your content field text contains an apostrophe, either try to change the copy or replace the quote character (') with the apostrophe character (’).