> For the complete documentation index, see [llms.txt](https://docs.payfacto.com/payfacto-knowledge/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.payfacto.com/payfacto-knowledge/uk-and-intl/applications/securetable/securetable-online-user-manual/troubleshooting.md).

# Troubleshooting

## Troubleshooting

### Microsoft .NET Framework 3.5 is missing

#### Issue Description:

While attempting to install STPISecure, an error message is displayed:

<figure><img src="/files/cqtmm1Oag4dsN5XKyveW" alt=""><figcaption></figcaption></figure>

STPISecure requires Microsoft .NET Framework 3.5.

Please use Windows Update / Windows Features to install this version, and then re-run the installer.

#### Solution:

Install Microsoft .NET Framework 3.5 through Windows Update or use the "Turn Windows features on or off" option from Add/Remove programs to enable .NET Framework 3.5.

<figure><img src="/files/FQk5JJJr26ZmFAPl0XbO" alt=""><figcaption></figcaption></figure>

<figure><img src="/files/rnFn2ro7B3lnK32BeplG" alt=""><figcaption></figcaption></figure>

Once Microsoft .NET Framework 3.5 is installed, retry installing STPISecure.

***

### Java is missing

#### Issue Description:

While attempting to install STPISecure, an error message is displayed:

<figure><img src="/files/qgRmQv3axUglWEfV86u4" alt=""><figcaption></figcaption></figure>

STPISecure requires Java version 1.8 or newer.

Please install this separately and then re-run the installer.

#### Solution:

Download and install Java from the Oracle website:

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<https://www.java.com/en/>

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Once Java is installed on your system, retry installing STPISecure.

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