The table below shows some of the problems that may be encountered using the Tree Growth module, with possible solutions.
| The macro RunModel could not be seen when the Alt-F8 key was pressed. | Macros were not enabled when MYRLIN#3 was opened. |
| A Visual Basic error message occurs when running RunModel, with a message such as 'Division by zero', 'Overflow', etc.. | Check the general parameters on the {models} sheet are reasonable. Zero or empty felling cycle, time interval cause these errors. Check the parameters are in the correct cells. |
| "Subscript out of range" error occurs when running RunModel | Various mis-settings to parameters could cause this. If the species groups are absent from the {models} sheet, or do not start in row 11, or refer to group codes unrelated to those in the StandTables sheet this may happen. It will also happen when MYRLIN#3 is not the active workbook when RunModel is executed. |
| The message 'Diameter class out of sequence' appears when running the model. | The diameter classes must be constructed in ascending order on the StandTables sheet. |
| Volumes continuously increase over time, or decline rapidly even without harvesting. | The AMR values may be in the wrong column, so that they are read as zero. Diameter increment figures may be absurd or in the wrong column. The recruitment factor should be around 1. If entered as a %, the cell must be formatted for % data. See the Growth Model topic for more information. |
| The message 'Stratum ... is in the {Areas} list but not in the model' appears when trying to run the model. | Check the names in the {Areas} list correspond with those in column A of the stand table. Leading or trailing spaces, or upper/lower case difference can cause a mismatch. The cell after the last entry in the {Areas} list must be empty. If it contains spaces, it may look empty, but will cause this error. See the Forest Description topic for more information. |
| Figures or tables do not appear as shown in the documentation when the model is run. | MYRLIN#3 may have been modified in a way that prevents it functioning properly. Please download the module again or revert to a saved backup. |