# Other Issues ## Calibration files not visible in file browser ### **Explanation** If the calibration file is not visible when using the [Load Calibration File ](https://docs.theiamarkerless.com/apollo-v2024/troubleshooting/pages/fuBTxVKbvavh0XLrjycG#id-5.3.-load-calibration-file)button or the [Assign Calibration Files](/apollo-v2024/theia3d-documentation/theia3d-dropdown-menus/tools-menu/assign-calibration-files.md) tool and the calibration file is an .xcp file exported by Vicon Nexus, the file browser window may be filtering for .txt files only. ### **Possible Solutions** Use the dropdown file filter selector in the file browser window to allow .xcp files to be shown. *** ## Theia3D freezes when attempting to open the application ### **Explanation** If Theia3D is failing to launch fully and is freezing after creating the main application window, this issue typically occurs after a change to the computer monitor setup. ### **Possible Solutions** To resolve this issue, open the Windows Registry Editor and navigate to the folder: Computer\HKEY\_CURRENT\_USER\Software\Theia. Right-click on the “Theia” folder, and choose delete. Close the Registry Editor, and restart the computer. After restarting, attempt to open Theia3D. This should allow the application to launch fully. *** ## Theia3D crashes when attempting to process a calibration or movement trial ### **Explanation** If Theia3D crashes when processing a calibration or movement trial, this issue is usually due to the GPU RAM becoming maxed out immediately when attempting to perform the processing. Typically, the root cause of this issue is too high of a GPU RAM requirement from the computer monitor setup, usually due to the use of multiple monitors or individual very high resolution monitors. ### **Possible Solutions** To reduce the GPU RAM requirements, try reducing the number or resolution of the monitors connected to the GPU. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.theiamarkerless.com/apollo-v2024/troubleshooting/other-issues.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.