x86 or x64 Build - vanjarosoftware/Vanjaro.Platform GitHub Wiki

By default, IIS application pools now run in 64 bit mode (x64) unless you specifically configure them to run in 32 bit mode. Azure Web Apps are configured to run in 32 bit mode by default. You can easily switch to 64 bit from Azure Portal or install the appropriate x86 build.

Vanjaro only supports 64 bit application pools.