If you’re reading this, you might have been told by SumatraPDF that you have a corrupted installation.
How can that happen?
SumatraPDF comes in two flavors: a portable version and an installer.
A portable version is a self-contained executable and cannot be corrupted.
An installer needs to be run to be properly installed. Part of it is extracting libmupdf.dll library.
There are 2 possible problem:
How to solve the problem?
If you want to place SumatraPDF in any location, under any name, use the self-contained portable flavor.
If you insist on using the installable version, just install it. The installer will run if it has -install in the name of the .exe (which it will if you download official build).
If you rename the .exe, you can force running the installer with -install option.
Alternatively, you can extract libmupdf.dll and all other files with -x option.

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