When create your layout did you use a Font that does not exit in users computers? If so, computer sometimes convert things badly into Wingdings.
This sounds like a known issue with FileMaker running on Windows
Some of the possible fixes by doing the following
- Update to the latest version of Adobe Reader.
- Delete the Windows font cache at C:\Windows\System32\FNTCACHE.DAT and restart the machine.
- Delete the Adobe cache inside C:\Users\<username>\AppData\Local\Temp\acrord32_sbx\
- Use a zoom level other than 100%.
I have included the link bellow to the help article bellow
Some fonts are replaced with an unreadable .tmp font
This can also be a sign of corruption in the database so I would recommend running a recovery on the Solution